THE THEORY OF FORECASTING EARTHQUAKES
the tectonic plates earthquakes did, then why the border does not
happen a few earthquakes in the same physical point? Facts show that
happens just one earthquake.
The moon makes tides in the oceans and seas, raising the water with their gravitational force.
But it raises the ground crust.In this time the moon "pulling" the trigger of earthquake.To predict an earthquake, you can track the geographical coordinates of the maximum uplift of the crust and to predict at what point it will pass over the already developed outbreak ...
In efforts to predict earthquakes, seismologists have investigated the association of an impending earthquake with such varied phenomena as seismicity patterns, crustal movements, ground water level in wells, radon or hydrogen gas emissions from the Earth, changes of seismic wave velocities, and electromagnetic fields (seismo-electromagnetics)
The mystery of earthquake occurrence frequently sparks people without scientific training into claiming that they have found the solution to the earthquake prediction problem. Discredited, fantastic theories of predicting earthquakes include weather conditions and unusual clouds, animal behavior, and the phases of the moon. These pseudoscientific ignore the requirement of rigorously formulating the hypothesis and to test it statistically. theories and predictions
Self-appointed prediction experts often resort to the technique of making vague statements, which they claim were correct predictions, after an earthquake has happened somewhere. Rudolf Falb's "lunisolar flood theory" is a typical example from the late 19th century.
Evaluation of prediction theories
Official earthquake prediction evaluation councils have been established in California (the California Earthquake Prediction Evaluation Council) and the federal government in the United States (the National Earthquake Prediction Evaluation Council), but have yet to endorse any method of predicting quakes as reliable.
Unless the following parameters are specified, a statement does not qualify as an earthquake prediction:
- A specific location or area
- A specific span of time
- A specific magnitude range
- A specific probability of occurrence
The sub-commission for earthquake prediction of IASPEI (International Association of Seismology and the Earth’s Interior) has reviewed claims of successful predictions and of proposed methods to predict during the 1990s. Their procedure was similar to reviews of proposals for research grants. Authors submitted their detailed research on the prediction problem. Anonymous reviewers commented, and members of the sub-commission discussed the merits of the proposal and of the reviewer’s comments.
A decision to place the claim into one of three categories (preliminary list of significant precursors, no decision, rejected) was then transmitted to the authors, who could write a reply, if they so wished. The entire exchange was then published, unless the authors did not agree to publication
Most of the nominated successful predictions and methods to predict were rejected. A brief summary can be found in Wyss and Booth. At that time, three methods seemed most promising: Seismicity patterns, ground water properties, and crustal deformations,
Attribution to a plausible physical mechanism lends credibility, and suggests a means for future improvement. Reproducibility and statistical analysis are used to distinguish predictions which come true due to random chance (of which a certain number are expected) versus those that have more useful predictive capability, and to validate models of long-term probability. Such models are difficult to test or validate because large earthquakes are so rare, and because earthquake activity is naturally clustered in space and time. "Predictions" which are made only after the fact are common but generally discounted.
Emission of radon as a quake precursor was studied in the 1970s and 80s with no reliable results and continued to be dismissed by most seismologists until recently. However, after the 2009 L'Aquila earthquake, which was preceded by an Italian laboratory technician's predictions of an impending major earthquake, some in the scientific community expressed renewed interest in radon as a quake precursor. In December 2009, the technician, Giampaolo Giuliani, presented his research to the American Geophysical Union in San Francisco and was later invited by the American Geophysical Union to participate in developing a worldwide seismic early warning system.
Further information: Radon#Scientific
The VAN method
Main article: VAN method
VAN is a method of earthquake prediction proposed by Professors Varotsos, Alexopoulos and Nomicos in the 1980s; it was named after the researchers' initials. The method is based on the detection of "seismic electric signals" (SES) via a telemetric network of conductive metal rods inserted in the ground. The method stems from theoretical predictions by P. Varotsos, a solid-state physicist at the National and Capodistrian University of Athens. It is continually refined as to the manner of identifying SES from within the abundant electric noise the VAN sensors are picking up. Researchers have claimed to be able to predict earthquakes of magnitude larger than 5, within 100 km of epicentral location, within 0.7 units of magnitude and in a 2-hour to 11-day time window.
Foreshocks are medium-sized earthquakes that precede major quakes.
An increase in foreshock activity (combined with purported indications like ground water levels and strange animal behavior) enabled the successful evacuation of a million people one day before the February 4, 1975 M7.3 Haicheng earthquake by the China State Seismological Bureau.
In 1969 Japanese seismologist Kiyoo Mogi proposed what has become known as the 'Mogi doughnut hypothesis', which suggests that major earthquakes tend to occur in an unusually seismically calm area surrounded by a ring of unusually high seismic activity.
In November 2005 (November 11 issue) the journal Physical Review Letters, published by the American Physical Society, published an article by researchers from Israel and Germany that says that there is a way to predict when the next earthquake will hit. Prof. Shlomo Havlin from Bar-Ilan University in Israel, in collaboration with Prof. Armin Bunde, of the Justus-Liebig University in Giessen, Germany, and Bar-Ilan University graduate student Valerie Livina used the "scaling" approach from physics to develop a mathematical function to characterize earthquakes of a wide range of magnitudes to learn from smaller magnitude earthquakes about larger magnitude earthquakes. The team's findings reveal that the recurrence of earthquakes is strongly dependent on the recurrence times of previous earthquakes. This memory effect not only provides a clue to understanding the observed clustering of earthquakes, but also suggests that delays in earthquake occurrences, as seen today in Tokyo and in San Francisco, are a natural phenomenon.
One possible method for predicting earthquakes, although it has not yet been applied, is fractoluminescence. Studies at the Chugoku National Industrial Research Institute by Yoshizo Kawaguchi have shown that upon fracturing, silica releases red and blue light for a period of about 100 milliseconds. Kawaguchi attributed this to the relaxation of the free bonds and unstable oxygen atoms that are left when the silicon oxygen bonds have broken due to the stresses within the rock.
The "Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions" satellite, constructed by CNES, has made observations which show strong correlations between certain types of low frequency electromagnetic activity and the most seismically active zones on the Earth, and have shown a sharp signal in the ionospheric electrondensity and temperature near southern Japan seven days before a 7.1 magnitude occurred there (on August 29 and September 5, 2004, respectively).
Quakesat is an earth observation nanosatellite based on 3 CubeSats. It was designed to be a proof-of-concept for collecting extremely low frequency earthquake precursor signals from space. The primary instrument is a magnetometer housed in a 2 foot (0.6 m) telescoping boom.
The ESPERIA Project
ESPERIA is an equatorial space mission mainly concerned with detecting any tectonic and preseismic related signals. More in general, it has been proposed for defining the near-Earth electromagnetic, plasma, and particle environment, and for studying perturbations and instabilities in the ionosphere-magnetosphere transition region. To study earthquake preparation processes and anthropogenic impacts in the Earth's surface, a phase A study has been realized for the Italian Space Agency.
An earthquake warning system is a system of accelerometers, communication, computers, and alarms that is devised for regional notification of a substantial earthquake while it is in progress. Japan, Taiwan and Mexico all have earthquake early-warning systems.
In a paper in the journal Nature, Richard Allen of the University of California claims that the distinction between small and large earthquakes can be made from the very first seconds of seismic energy recorded by seismometers, though other scientists are not convinced. If correct this may make earthquake early warning (as distinct from prediction) more powerful. Earthquake early warning provides an alarm that strong shaking is due soon to arrive, and the more quickly that the magnitude of an earthquake can be estimated, the more useful is the early warning. However, earthquake early warning can still be effective without the ability to infer the magnitude of an earthquake in its initial second or two.
Animal early warning
Animal behavior reports are often ambiguous and not consistently observed. In folklore, some animals have been identified as being more able to predict earthquakes than others, especially dogs, cats, chickens, horses, toads and other smaller animals.
It has been postulated that the reported animal behavior before an earthquake is simply their response to an increase in low-frequency electromagnetic signals. The University of Colorado has demonstrated that electromagnetic activity can be generated by the fracturing of crystalline rock. Such activity occurs in fault lines before earthquakes. According to one study, electromagnetic sensors yield statistically valid results in predicting earthquakes.
In Italy, findings from 2009 suggest that toads are able to detect pre-seismic cues.
There are two flavors of tidal stressing that have been claimed to generate enhanced rates of earthquakes—diurnal and biweekly tides. The diurnal correlations would arise from more earthquakes only during the hours when the tidal stress is pushing in an encouraging direction, in contrast, biweekly effects would be based on earthquakes occurring during the days when the sinusoidal stressing oscillations are largest. The former, as most easily observed in the twice-daily rise and fall of the ocean tides, have occasionally been shown to influence earthquakes (e.g.,, this paper shows there may be some weak tidal triggering of shallow, oceanic thrust-faulting earthquakes). The latter, which arises from the periodic alignment of the Sun and Moon, has often been claimed in the popular press to incubate earthquakes (sometimes termed the "syzygy" effect) and occasionally for small datasets in the scientific literature (e.g.,), but generally such effects do not appear in careful studies of large datasets.
A paper published in Taiwan, by the Department of Astornomy, Beijing Normal University, found a significant relationship to tidal forces and earthquakes in China and Taiwan. The paper considers the relationship between 21 major earthquakes (Ms ≥ 7.0) in land and the offshore area of Taiwan island in the 20th century and the variance ratio of the lunar-solar tidal force. The result indicates that the time of these earthquakes is closely related to the variance ratio of the lunar-solar tidal force, and therefore that the tidal force possibly plays an important role in triggering earthquakes. The conclusion is this method may be used to help forecast earthquakes by studying the lunar perigee.
Syzygy, which is not given much credence in the scientific community, is motivated by the observation that, historically, there have been some great earthquakes whose timing coincides with tidal forces near their maximum. For maximum tidal force, three factors must coincide: first, when the moon (in its elliptical orbit) is closest to the earth; second, when it is within a day or two of a new moon (so that the tidal forces of the moon and sun are acting in concert); and third, when the earth (in its elliptical orbit) is at or near its closest distance to the sun.
In the above methods for predicting earthquakes missing precursor, which predict earthquakes.