Earthquake forecast
from space
N.Danilkin specialfor the "news of cosmonautics"
One of the most terrible misfortunes of humanity, which yearly takes away tens of thousands of human lives, are earthquakes. In connection with the fact that they present large danger to life and health of people, are caused enormous destruction and negative economic consequences, scientists attempt to find means if not for dealing with earthquakes themselves, then at least for their confident prognostication. Contemporary science persistently attempts to find answers to two questions: where and when will happen sequential earthquake?
On the planet is created the entire network of seismic stations, which makes it possible to practically error-free determine the position of the future epicentre of earthquake. Scientists sufficiently confidently can forecast energy of future push (or a series of pushes), and also depth of the presence of the earthquake center under the earth's surface. Thus, to a question "where?" scientists answer confidently and unambiguously.
However, the second question not always it is possible to answer definitely. There are many different methods, with the aid of which on the basis of those or others it is indicative the being approached earthquake it is possible to predict its first push. There are methods of predicting the future earthquake on the basis of the registration of physical, chemical, geological and even biological phenomena, but their reliability does not make it possible to give precise answer to a question "when?".
In the scientific prediction of various phenomena there is a concept "flow of false alarms". If any system is in the state of the expectation of a certain event and must predict its beginning on the basis of the precise measurement of one or other parameter or another, then it is important, as frequently it will make mistakes. How often it will raise false alarm in the course of the month? During the year? It occurs that the flow of false alarms practically from all known methods of the forecast of earthquakes is too great in order to speak about existence of reliable method. The value of error kolebletsya from several weeks to decades. The sometimes forecasted earthquake does not occur generally. But indeed the price of incorrect forecast in this case is very high. This of life and the health of people, this economic and material prosperity of entire regions.
Essential progress was outlined for the last 10- anniversary in this complex question. It was explained that from the space distance to predict the time of the beginning of earthquake it is considerably simpler than near. Scientists ascertained that to different parameters of near-earth outer space and on the state of space weather the future earthquake has an essential effect. The most sensitive region is the ionosphere, i.e., the ionized part of the earth's atmosphere, which is located tentatively in the region of heights from 70 to 700 km above the earth's surface. Even name appeared: "ionospheric foreshocks" - the elaborate complex of the phenomena of electromagnetic nature, recorded, first of all, with the aid of ISZ - ARTIFICIAL EARTH SATELLITE. Onboard studies have the low accuracy of the determination of the position of the future epicentre of earthquake, but they better than other methods make it possible to answer a question "when?" and as the most important component they must enter into the comprehensive program of the forecast of earthquakes. Ionospheric foreshocks are manifested in the form of specific variations in the parameters of space plasma, electrical and magnetic quasi-permanent pour on and electromagnetic waves, the flows of energetic particles. The characteristic property of the observed variations is the fact that they are recorded in the specific region of space, whose projection on the earth's surface includes the position of the epicentre of future earthquake. Certainly, different forerunners have different probability of the precise prediction of earthquakes and, correspondingly, different flow of false alarms.
In 2001 the special Committee of Experts, created Shityu rosaviakosmosom, conducted the comparative study of all possible methods of the prediction of earthquakes with the aid of KA and determined the promising. In their number - radiosounding the ionosphere from the satellites, and the most promising instrument named ionosonde. (let us again emphasize that were named most promising instrument and method, but not only. A question is so complex that only complex study of all sides of the process of shaping of earthquake promises hope for its precise prediction.)
Without going in detail into the fairly complicated theory of origin and existence of ionospheric forerunners, let us note that the essential onset of a forerunner is the formation above that region of the Earth, where there will be the future epicentre of earthquake, zone of the increased or lowered electron density at the height where the electron concentration is maximum. But here is the misfortune: the level of exceeding electron density, caused by the action of foreshock, above the index of background state according to the contemporary ideas is not more than 20-25%. Therefore the procedure of the presence of forerunner must rest on a constant patrolling of the zone, where is expected earthquake, and constant determination of the background state, whose change can give the prediction of the moment of the beginning of earthquake. The latter means that the space ionosonde, which predicts earthquakes, must simultaneously accomplish the tasks of ionospheric service, which at present rests only on the ground-based ionosondes, which are been the basic instruments of ground-based ionospheric observatories. This to a considerable degree complicates space experiment itself, it forces to make the data reduction process by that fully automated, which, in turn, leads to the need of creating the ionosonde on the basis of the polarization separation of signals and other complexities.
The connection between the earthquakes and the state of the ionosphere is studied by scientists in the different countries of peace. The described diagram of ionospheric forerunners rests in essence on studies of scientists from the institute of terrestrial magnetism, ionosphere and radiowave propagation (IZMIRAN - INSTITUTE OF TERRESTRIAL MAGNETISM, THE IONOSPHERE AND RADIO WAVE PROPAGATION OF THE ACADEMY OF SCIENCES, USSR), first of all the doctors physico-mathematical of the sciences Of s.A.Pulintsa and V.N.Orayevskogo. However, recently appeared the new hypothesis, expressed by professor yu.K.Kalinin from the institute of applied geophysics of the Russian Federal Service on Hydrometeorology and Environmental Control. Analyzing data of the time variations in the density of the ionosphere in its maximum on different ionospheric observatories of planet on the basis of the application of contemporary statistical methods, Yu.Kalinin found the new type of ionospheric heterogeneities, speaking in general terms, the ionospheric clouds of large sizes. These clouds are created above the epicentre of future earthquake long before the beginning of the first push. Then they "are torn off" from this place and in accordance with the wind and electromagnetic conditions at the appropriate height they begin to move above the planet, passing is sometimes during several hour tens of thousands of kilometers. In the period of this motion they can be recorded by ground-based or onboard ionosondes.
The confirmation of hypothesis illustrates Fig. 1. On the map circles showed ionospheric observatories; variations in the parameters obtained by them were used for the statistical analysis. It turned out that with respect to three observatories (they were noted Rome - red, Ahmadabad, Darwin) variation determined the presence of the motion above them of the ionospheric clouds of the increased density. Above the remaining relatively closely spaced observatories (in the yellow circles it is set sign "-") of analogous motions it was discovered not. Kalinin considers that above the region of the future earthquake (noted by letter "E") arose the heterogeneity, which then began to move along the black dotted line. When it passed above the observatory into g.Darvin (Australia), then it was for the first time registered. This occurred 12 it was hour prior to the first push of earthquake, which happened subsequently, by the force of 5.6 marks. In the space between Rome and London it completely was decomposed and above London registered not was.
The hypothesis Of yu.Kalinina can become theory after its repeated confirmation by other principally experiments. In this case this confirmation occurred. At the moment of moving the heterogeneity above southeastern Asia its way interesected the trajectory of motion BY OS "Mir", on which worked onboard ionosonde. Station find at this time of lower than the maximum of electron density in the ionosphere. The work of ionosonde under the field of maximum - this is the pioneer study of Russian scientists (NK No.11, 2001, c.24), which for the first time in the world practice made it possible to see ionospheric heterogeneities not on the basis of statistical analysis, but, as the saying goes, with own eyes, because of the presence of the special type of the trajectories of radio waves, returned by the described heterogeneity to the satellite. This heterogeneity is visible on a series of the ionograms, where the trajectory of the station and the moving clouds of electrons intersected. Fig. 1 below shows three ionograms from this series. Green points on the ionograms marked the tracks of the described above recovered on ISZ - ARTIFICIAL EARTH SATELLITE rays, which will probe the ionosphere.
Fig. 2 shows the quantitative calculation of the similar case of the "vision" of ionospheric cloud and some of its parameters are given.
The upper fragment of figure shows the to the left height dependence of electron density on the height, which was calculated from the same ionograms. The height of the maximum of density and the density of plasma at the height of station are noted (fs). Are indicated also the height of the arrangement of maximum (360 km) and the height are indicated also the height of the arrangement of maximum (360 km In the right side of the upper fragment is given the internal structure of the cloud, along outer boundary of which flies in the right side of the upper fragment is given the internal structure the "recurrent" (there is in the form into the point of emission) trajectories of radio waves. In the lower part of the fragment an assayed ionogram and its model is shown.
Thus, if the hypothesis Of yu.Kalinina about the appearance and the motion subsequently of the completely special ionospheric heterogeneities, which appear only above the region of the prepared earthquake, proves to be correct, then sounding the ionosphere from the satellite, located below height of the maximum of the ionosphere, makes it possible "to see" this heterogeneity. In this case the need for the prolonged and complex calculations of the background state of the ionosphere above each earthquake-hazard zone is eliminated. The role of the manned space stations, which fly of necessity for radiation safety in the equatorial latitudes lower than height of the maximum of the ionosphere and having of the on-duty operator, which in any point of the intersection of the trajectory of station and trajectory of cloud can "notch" dangerous cloud, becomes the determining with the creation system of the prognostication of earthquakes.
It should be noted that it should be noted that station "Mir" orbit proved to be very convenient tool for similar observations. Unfortunately, ionospheric studies on it were conducted only during one year. Nevertheless was obtained a large quantity of ionograms, which show the presence in the ionosphere of the "electron clouds of Kalinin", whose sizes were unprecedented in ionospheric studies. Fig. 3 shows the case of registering the described heterogeneity of planetary scales, by the discovered station "Mir" in the region of Japanese islands. In the upper part of the figure is given the ionogram, on which, just as on of the previous, the tracks recurrent trajectories are markirovany by green color. The trajectory of station and the region (it is marked red), is below to the left shown, above which the heterogeneity was fixed. To the right red square shows the place, where the given ionogram was fixed.
I think that in the reader the impression has already been formed, that the hypotheses Of pulints and Kalinin do not contradict each other, but faster together is described one and the same phenomenon. Actually, during the first stage electron cloud is formed above the epicentre of future earthquake in the region of the maximum of the ionosphere long before the first push, as it escapes from theoretical works and practical studies Of pulintsa and Orayevskogo. In this case on resultant cloud wind and electromagnetic forces act, displacing the geometric center of cloud in the appropriate direction. When source weakens its action or ceases completely, cloud begins to be moved above the planet under the action of the described forces and in complete agreement with the hypothesis and the statistical calculations of Kalinin.
Thus, the conclusion of the experts Of rosaviakosmosa the fact that onboard ionosonde is the most promising instrument for recording of foreshocks, considerably was strengthened after the appearance of Kalinin's hypothesis. Actually, the group of the automatic spacecraft with onboard ionosondes, which control earthquake-hazard zones to the object of the detection of forerunners, simultaneously it will be independent check motion above the planet of the "clouds of Kalinin". The detection of forerunner in both so differing from each other experiments will considerably strengthen the probability of the correct prediction of the time of the beginning of earthquake and, correspondingly, svedet to the minimum the flow of false alarms. All this, however, it requires the even continuance of experimental check of both expressed hypotheses.
The discoveries, which were made at the discoveries, which were made at station "Mir" phenomena on the basis of fundamentally new experiment - radiosounding the ionosphere of the region of lower than the peak of ionization (NK No.8, 1999, c.56). Today, when it is well known that precisely should be searched for - the differences from the background and the "cloud of Kalinin", the reasonably set space experiment can considerably draw nearer the time of the scientific prediction of earthquake. In this sense the installation of ionosonde on board the Russian segment S (which, just as in this sense the installation of ionosonde on board the Russian segment S (which, just as station "Mir" Specifically, Russian scientists conducted the described pioneer studies, and precisely their experience can be most useful for the formation of final conclusions.