statistical analysis of the results of earthquake prediction based on bursts of aftershocks abstract the premonitory seismicity pattern described as a burst of aftershocks is analysed in 13 regions of the world its high statistical significance is ascertained the mathematical approach developed here may be useful in the analysis of other earthquake precursors

diagnosis of time of increased probability of strong earthquakes in different regions of the world algorithm cn abstract an algorithm for intermediate term earthquake prediction is suggested which allows diagnosis of the times of increased probability of strong earthquakes tips tips are declared for the time period of one year and an area with linear dimensions of a few hundred kilometers and can be extended in time the algorithm is based on the following traits of an earthquake flow level of seismic activity its temporal variation clustering of earthquakes in space and time their concentration in space and their long range interaction the algorithm is normalized so that it can be applied in various regions without readaptation tips diagnosed by the algorithm precede 80 of strong earthquakes and take on average 24 of the total time

localization of intermediate term earthquake prediction relative seismic quiescence within a region which has already been diagnosed as having entered a time of increased probability tip for the occurrence of a strong earthquake can be used to refine the locality in which the earthquake may be expected to occur a simple algorithm with parameters fitted from the data in northern california preceding the 1980 magnitude 7 0 earthquake offshore from eureka depicts relative quiescence within the region of a ttp the procedure was tested without readaptation of parameters on 17 other strong earthquake occurrences in north america japan and eurasia most of which were in regions for which a tip had been previously diagnosed the localization algorithm successfully outlined a region within which the subsequent earthquake occurred for 16 of these 17 strong earthquakes the area of prediction in each case was reduced significantly ranging between 7 and 25 of the total area covered by the tip

intermediate term prediction in advance of the loma prieta earthquake the loma prieta earthquake of october 17 1989 was predicted by the use of two pattern recognition algorithms cn and m8 the prediction with algorithm cn was that an earthquake with magnitude greater than or equal to 6 4 was expected to occur in a roughly four year interval staring in midsummer 1986 in a polygonal spatial window of approximate average dimensions 600 times 450 km encompassing northern california and northern nevada the prediction with algorithm m8 was that an earthquake with magnitude greater than or equal to 7 0 was expected to occur within 5 to 7 years after 1985 in a spatial window of approximate average dimensions 800 times 560 km the predictions were communicated in advance of the earthquake in previous mainly retrospective applications of these algorithms successful predictions occurred in about 80 of the cases

prediction of a subsequent large earthquake abstract many large earthquakes come in pairs separated by relatively small times and distances the subsequent earthquake may be a large aftershock of the first one or another main shock the prediction of a subsequent large earthquake is important for reducing the great hazard caused by destabilization of buildings lifelines and other constructions mountain slopes etc after the first large earthquake an algorithm for prediction of a subsequent large earthquake is based on analysis of the aftershock sequence following a first shock and of local seismic activity preceding it the algorithm was found by analysis of 21 large earthquakes in the california nevada region six of them were followed by subsequent large earthquakes in application to these earthquakes the algorithm made one error a failure to predict then this algorithm with all parameters fixed was tested retrospectively on independent data in different regions of the world it was applied to 98 large earthquakes not considered in its development 10 of them were followed by a subsequent large shock there were two failures to predict and four false alarms since 1989 20 advance predictions have been made including the 1991 rachi earthquake in georgia caucasus and three californian earthquakes loma prieta 1989 joshua tree 1992 and northridge 1994 among three mistakes two were false alarms and one was a failure to predict both the advance and retrospective predictions were made by the fixed algorithm previously developed and unambigously defined in publications the statistical significance of advance predictions exceeds 98

the statistical mechanics of earthquakes abstract we review recent theoretical developments on the physics of earthquakes in particular we focus on the rise of the statistical mechanical view of earthquakes as a kind of phase transition this view is appealing in light of the well known scaling relations such as the gutenberg richter magnitude frequency and omori s law of aftershock decay scaling relations such as these which are in reality power laws are known to be associated with dynamical systems residing near a critical point in the state space of the system these second order critical points are associated with second order transitions which are a result of gradual changes of the controlling parameters at the same time characteristic earthquakes which involve the entire fault segment sliding nearly at once are more reminiscent of a first order transition which is characterized by sudden widespread changes in the physical state of the system in this paper we review these ideas and show how recent developments are leading to a view of earthquake fault systems based on modern statistical mechanics

refolded nappes formed during late archaean terrane assembly godthabsfjord southern west greenland recent work has provided a new tectono metamorphic framework for the archaean evolution of the godthabsfjord region which can be divided into discrete tectonic units each characterized by different magmatic structural and metamorphic histories these tectonic units were assembled in the late archaean post 2750 ma the present structural patterns seen in the region date from the period 2750 2600 ma and do not reflect earlier structural events as was previously considered late archaean structural evolution began with a period of interthrusting of early archaean sialic and late archaean oceanic crustal segments coeval with or followed by isoclinal nappe formation under amphibolite facies conditions linear fabrics in early archaean rocks were rotated into parallelism with those newly formed parallel to f1 hinge lines in the late archaean rocks a second major thrusting event emplaced granulite facies rocks structurally on top of the amphibolite facies rocks subsequent to this event a series of f2 upright or steeply inclined basin and dome structures formed some of which have sheath morphology this second folding episode acting upon the isoclinal nappes produced the regional scale interference patterns observed the early linear fabrics were re oriented around these second generation structures data are produced from selected areas to illustrate the fabric patterns and structural continuity that exists throughout the region

modelling of block structure dynamics parametric study for vrancea the dependence of synthetic earthquake catalog obtained by numerical modelling of block structure dynamics for the vrancea romania seismoactive region on values of the model parameters is studied the features of the synthetic seismicity such as the spatial distribution of epicentres the level of seismic activity the relative activity of the different faults are considered as functions of the directions of motions of the different blocks of the structure the likelihood of the features of the synthetic and of the real seismicity could be used as criterion for the reconstruction of the direction of the tectonic motions

coupled stress release model for time dependent seismicity based on the original stress release model of seismicity proposed by vere jones 1978 this paper has developed a stochastic coupled stress release model of time dependent seismicity which considers the earthquake interaction and stress transfer between different seismic subregions as an example the model is applied to a statistical analysis of the historical earthquake catalog with magnitude m 6 0 during the period from 1480 to 1996 in north china according to the akaike information criterion aic the results show that the coupled stress release model is better than the original model which demonstrates the existence of long range correlations between different seismic subregions we also apply both the stochastic original and developed coupled models to analyze the synthetic catalog produced by a cellular automata model which is based on mechanics of a slide spring damper system to model the fault network the stress release model provides a good fit to the synthetic regional stress and the coupled stress release model provides an improvement in fit to the synthetic catalog over the original model

increased long range intermediate magnitude earthquake activity prior to strong earthquakes in california we study the space time relationships between strong earthquakes in california and the intermediate magnitude earthquakes that both precede and follow them all 11 earthquakes in california with nominal magnitudes greater than or equal to 6 8 from 1941 to 1993 were preceded by an increase in the rate of occurrence of earthquakes having magnitudes greater than 5 1 ten of the 11 earthquakes occurred when or shortly after the intermediate magnitude activity was greater than its 75th percentile three of these strong earthquakes are in a conventional space time foreshock aftershock relationship with others of the 11 strong events the precursory activity is concentrated in regions having linear dimensions of the order of a few hundred kilometers these dimensions are significantly larger than the estimated fracture lengths of the ensuing strong earthquakes the correlations are ill defined for smaller earthquakes and are almost unidentifiable for earthquakes with magnitudes less than about 4 6 the precursors to the strong earthquakes appear over a time interval of the order of 5 to 10 years before the strong earthquake although the onset was about 25 years before the san francisco earthquake in the case of the loma prieta and san francisco earthquakes the onset of increased activity appears to be relatively abrupt the increased activity is either switched off abruptly to distances of the order of hundreds of kilometers shortly after the occurrence of a strong earthquake or the strong events are themselves part of a precursory pattern of continuing high activity before a second strong earthquake that takes place soon thereafter with subsequent extinction of activity after it thus the intermediate magnitude precursors do not directly influence the time and location of the subsequent strong event but the strong event has a strong influence on the stress field in the vicinity of intermediate magnitude earthquakes to distances of the order of many times the scale size of the strong earthquake

patterns of seismic activity preceding large earthquakes we analyze the patterns of seismic activity which precede large events in a mechanical model of a fault the model generates a statistical distribution of events similar to that observed for a single fault with a scaling region consistent with the gutenberg richter law at small and moderate magnitudes and an excess of events at large magnitudes we find only slight variation in the scaling behavior during a loading cycle however we do observe systematic variations in space and time of the overall rate of activity in the model the activity accelerates dramatically preceding a large event and is usually a maximum hi the neighborhood of the future epicenter these results are compared to california seismicity data where we find that activity patterns vary regionally looking at patterns of activity in the san francisco bay area since 1948 we find an increase of activity on the calaveras fault near san jose beginning in the 1980s which if our model is relevant would forecast a large earthquake in that region the 1989 loma prieta earthquake occurred on the san andreas fault within 30 km of the section of the calaveras fault showing increased activity

geometric incompatibility in a fault system abstract interdependence between geometry of a fault system its kinematics and seismicity is investigated quantitative measure is introduced for inconsistency between a fixed configuration of faults and the slip rates on each fault this measure named geometric incompatibility g depicts summarily the instability near the fault junctions their divergence or convergence unlocking or locking up and accumulation of stress and deformations accordingly the changes in g are connected with dynamics of seismicity apart from geometric incompatibility we consider deviation k from well known saint venant condition of kinematic compatibility this deviation depicts summarily unaccounted stress and strain accumulation in the region and or internal inconsistencies in a reconstruction of block and fault system its geometry and movements the estimates of g and k provide a useful tool for bringing together the data on different types of movement in a fault system an analog of stokes formula is found that allows determination of the total values of g and k in a region from the data on its boundary the phenomenon of geometric incompatibility implies that nucleation of strong earthquakes is to large extent controlled by processes near fault junctions the junctions that have been locked up may act as transient asperities and unlocked junctions may act as transient weakest links tentative estimates of k and g are made for each end of the big bend of the san andreas fault system in southern california recent strong earthquakes landers 1992 m 7 3 and northridge 1994 m 6 7 both reduced k but had opposite impact on g landers unlocked the area whereas northridge locked it up again

upper ocean circulation in the glacial north atlantic from benthic foraminiferal isotope and trace element fingerprinting benthic cd ca and 13c records from the midlatitude and northern north atlantic are used to derive nutrient inventories and water mass distribution patterns for the past 50 000 years inferred holocene water column cd concentrations cdw and 13c values are 0 17 0 24 nmol kg 1 and 1 0 1 3 peedee belemnite pdb which document the dominance of nutrient depleted mediterranean outflow water mow and upper north atlantic deep water unadw glacial benthic cd ca and 13c indicate a continued contribution of unadw to the northern north atlantic and upper portuguese margin cdw 0 08 nmol kg 1 13c 1 86 pdb at the upper moroccan margin glacial cdw 0 23 nmol kg 1 is higher and 13c 1 44 pdb is lower during heinrich events benthic 13c decreases by up to 1 3 and peak cd ca increases by 0 1 0 14 mol mol 1 water column phosphorus equivalents are 1 8 2 8 mol kg 1 the combined cd ca and 13c pattern indicates that during mean glacial conditions antarctic intermediate water aaiw reached the midlatitude northeast atlantic 30 n during heinrich events aaiw contribution maximized so that southern hemisphere waters filled the north atlantic basin from bottom water to middepth levels

spatiotemporal patterns in the energy release of great earthquakes for the past 80 years the energy released in great strike slip and thrust earthquakes has occurred in alternating cycles of 20 to 30 years this pattern suggests that a global transfer mechanism from poloidal to toroidal components of tectonic plate motions is operating on time scales of several decades the increase in seismic activity in california in recent years may be related to an acceleration of global strike slip moment release as regions of shear deformation mature after being reached by stresses that have propagated away from regions of great subduction decoupling earthquakes in the 1960s

premonitory spreading of seismicity over the faults network in southern california precursor accord 1 we establish a connection between geometry of the faults network in a region and seismicity preceding the strong earthquakes in the intermediate term timescale of years previous studies of observed and computer simulated seismicity demonstrated that strong earthquakes are preceded in that timescale by the rise of seismic activity in a lower magnitude range here we explore a complementary phenomenon spreading of activity over the fault network this phenomenon is depicted by the seismicity pattern accord defined as a simultaneous rise of seismicity in a sufficiently large number of fault zones hence its name pattern accord has been found recently in synthetic seismicity generated by the colliding cascades cc model the present study demonstrates this pattern in observed seismicity of southern california we applied to observations a prediction algorithm based on the pattern accord scaled to the target magnitude 7 5 the pattern accord emerges within a few years before each of the three largest earthquakes in southern california kern county 1952 landers 1992 and hector mine 1999 and at no other time scaled to the target magnitude interval from 6 5 to 7 4 the pattern accord precedes six out of nine earthquakes the duration of alarms in both cases is about 30 of the time considered we repeated prediction with different combinations of adjustable numerical parameters of the algorithm summing up the success and error scores on an error diagram this numerical experiment shows that the prediction results are stable under moderate variations of adjustable parameters the final test would be as always an advance prediction the pattern accord has a simple physical explanation connected with equilibrium of the crustal blocks system under the impact of tectonic driving forces at the same time accord is a manifestation of a broader phenomenon premonitory increase of earthquakes correlation range the latter phenomenon was found for the first time in the cc model although it was hypothesized by one of the authors much earlier

precursory activation of seismicity in advance of the kobe 1995 m 7 2 earthquake a succession of precursory changes of seismicity characteristic to earthquakes of magnitude 7 0 7 5 occurred in advance of the kobe 1995 m 7 2 earthquake using the japan meteorological agency jma regional catalog of earthquakes the m8 prediction algorithm keilies borko and kossobokov 1987 recognizes the time of increased probability tip for an earthquake with magnitude 7 0 7 5 from july 1991 through june 1996 the prediction is limited to a circle of 280 km radius centered at 33 5 n 133 75 e the broad area of intermediate term precursory rise of activity encompasses a 175 by 175 km square where the sequence of earthquakes exhibited a specific intermittent behavior the square is outlined as the second approximation reduced area of alarm by the mendocino scenario algorithm msc kossobokov et al 1990 moreover since the m8 alarm starts there were no swarms recorded except the one on 9 26 nov 1994 located at 34 9 n 135 4 e time location and magnitude of the 1995 kobe earthquake fulfill the m8 msc predictions its aftershock zone ruptured the 54 km segment of the fault zone marked by the swarm directly in the corner of the reduced alarm area the kobe 1995 epicenter is less than 50 km from the swarm and it coincides with the epicenter of the m 3 5 foreshock which took place 11 hours in advance

premonitory raise of the earthquakes correlation range lesser antilles abstract we apply to the observed seismicity of lesser antilles a short term earthquake precursor which has been recently found by analysis of synthetic seismicity the latter was generated by a lattice type colliding cascades model of interacting elements precursor named roc depicted premonitory increase of the earthquakes correlation range here this precursor is used as a second approximation to the intermediate term prediction as a first approximation we use the alarms determined in the previous publication by the algorithm seismic reversal sr it depicts premonitory reversal of territorial distribution of seismicity we consider combined performance of both algorithms in prediction of earthquakes with magnitude 5 5 or above four such earthquakes occurred in the territory considered during 1984 1998 the alarms occupy 0 5 of the total time space three alarms happened to be correct two alarms were false and one earthquake was missed by prediction the alarms are very stable to variation of adjustable parameters of prediction method in view of this stability such a prediction is unusually good even for retrospective analysis we present this prediction method as a hypothesis to be tested on advance prediction

numerical modelling of earthquake flow in the southeastern carpathians vrancea effect of a sinking slab abstract the earthquake prone vrancea region is modelled as a system of perfectly rigid blocks separated by infinitely thin plane faults the interaction of the blocks along the fault planes and with the surrounding medium is assumed to be a viscous elastic the displacements of the block system are caused by motions of boundary blocks the velocities of the motions are found from a model of mantle flows induced by a sinking slab beneath the vrancea region when a ratio of stress to pressure for some portion of a fault plane exceeds a certain strength level a stress drop earthquake occurs as a result of the numerical simulation a catalog of synthetic earthquakes is produced several numerical experiments for various model parameters show that the spatial distribution of synthetic events is significantly sensitive to the directions of the block movements small variations in a slab rotation control the pattern of the synthetic seismicity the results of the analysis show that the catalogs obtained by the simulation of the block structure dynamics have certain features similar to those of the real earthquake catalog of the vrancea region

scale dependence in earthquake phenomena and its relevance to earthquake prediction abstract the recent discovery of a low velocity low q zone with a width of 50 200 m reaching to the top of the ductile part of the crust by observations on seismic guided waves trapped in the fault zone of the landers earthquake of 1992 and its identification with the shear zone inferred from the distribution of tension cracks observed on the surface support the existence of a characteristic scale length of the order of 100 m affecting various earthquake phenomena in southern california as evidenced earlier by the kink in the magnitude frequency relation at about m3 the constant corner frequency for earthquakes with m below about 3 and the sourcecontrolled fmax of 5 10 hz for major earthquakes the temporal correlation between coda q 1 and the fractional rate of occurrence of earthquakes in the magnitude range 3 3 5 the geographical similarity of coda q 1 and seismic velocity at a depth of 20 km and the simultaneous change of coda q 1 and conductivity at the lower crust support the hypotheses that coda q 1 may represent the activity of creep fracture in the ductile part of the lithosphere occurring over cracks with a characteristic size of the order of 100 m the existence of such a characteristic scale length cannot be consistent with the overall self similarity of earthquakes unless we postulate a discrete hierarchy of such characteristic scale lengths the discrete hierarchy of characteristic scale lengths is consistent with recently observed logarithmic periodicity in precursory seismicity

patterns of seismic release in the southern california region southern california experiences earthquakes on the san andreas system of vertical right lateral predominantly strike slip faults and on a second system of faults that includes thrusts oblique slip left lateral and other faults pattern recognition and cluster analysis are used to analyze the catalog of earthquakes with magnitudes 5 5 from 1915 to 1994 we use pattern recognition to find a suite of traits that would characterize each of these two systems and distinguish them from each other both pattern recognition and cluster analysis show that epochs of seismic release occur in which one or the other system is the predominant form of earthquake activity for the past 2 decades the second system has been the active one small changes in the direction of plate movements could account for this phenomenon seismic release on the san andreas system is preceded by episodes of activity in the great basin or in the gulf of california presumably these episodes would represent extension in the former region and spreading and slip on transform faults in the latter

patterns of stress corrosion geometry of the principal stresses we investigate migration of fluids through the rock in the stress corrosion process the fluids migrate along the trajectories of the principal stress field we study geometry of these trajectories including singularities limit cycles and possible bifurcations we describe corresponding configurations of weakened zones in the lithosphere due to the fluid migration

colliding cascades model for earthquake prediction a wide set of premonitory seismicity patterns is reproduced on a numerical model of seismicity and their performance in the prediction of major model earthquakes is evaluated seismicity is generated by the colliding cascades model recently developed by the authors the model has a hierarchical structure it describes the interaction of two cascades a direct cascade of loading which is applied to the top largest element and transfers down the hierarchy and an inverse cascade of failures which goes up the hierarchy from the smaller to the larger elements these cascades collide and interact loading leads to failures while failures release and redistribute the loading three basic types of earthquake precursors are considered i the clustering of earthquakes in space and time ii the intensity of earthquake sequences and iii the correlation distance between earthquakes patterns of the first two types are used in intermediate term earthquake prediction algorithms patterns of the third type are found in the colliding cascades model although they were hypothesized previously they have not been validated by observations for each precursor we explore what is called an error diagram showing the total duration of alarms the rate of failures to predict and the rate of false alarms

intermediate term earthquake prediction an earthquake of magnitude m and linear source dimension l m is preceded within a few years by certain patterns of seismicity in the magnitude range down to about m 3 in an area of linear dimension about 5l 10l prediction algorithms based on such patterns may allow one to predict approximately 80 of strong earthquakes with alarms occupying altogether 20 30 of the time space considered an area of alarm can be narrowed down to 2l 3l when observations include lower magnitudes down to about m 4 in spite of their limited accuracy such predictions open a possibility to prevent considerable damage the following findings may provide for further development of prediction methods i long range correlations in fault system dynamics and accordingly large size of the areas over which different observed fields could be averaged and analyzed jointly ii specific symptoms of an approaching strong earthquake iii the partial similarity of these symptoms worldwide iv the fact that some of them are not earth specific we probably encountered in seismicity the symptoms of instability common for a wide class of nonlinear systems

a renormalization group approach to the stick slip behavior of faults we treat a fault as an array of asperities with a prescribed statistical distribution of strengths when an asperity fails the stress on the failed asperity is transferred to one or more adjacent asperities for a linear array the stress is transferred to a single adjacent asperity and for a two dimensional array to three adjacent asperities using a renormalization group rg method we investigate the properties of a scale invariant hierarchical model for the stochastic growth of fault breaks through induced failure by stress transfer an extrapolation to arbitrarily large scales shows the existence of a critical applied stress at which the solutions bifurcate at stresses less than the critical stress virtually no asperities fail on a large scale and the fault is locked above the critical stress asperity failure cascades away from the nucleus of failure we interpret this catastrophic failure as an earthquake and it corresponds to the transition from stick to slip behavior on the fault thus the stick slip behavior of most faults can be attributed to the distribution of asperities on the fault we propose our stochastic mechanism as an alternative to the traditional hypotheses for the stick slip behavior of faults a major advantage of our approach is the inclusion of scale invariance thus the observed frequency magnitude relation for seismicity is a natural consequence of our basic hypothesis

predictive modeling of the seismic cycle of the greater san francisco bay region the seismic cycle for the san francisco bay region is synthesized by a model combining the pre and post 1906 seismic histories the long term acceleration of seismic release seismic moment benioff strain release or event count in the seismic cycle and the shorter term accelerations preceding the larger earthquakes within that cycle are modeled using an empirical predictive technique called time to failure analysis in which rate of seismic release is proportional to an inverse power of the remaining time to failure the exponent of time to failure in the accelerating sequences appears to be scale invariant and the length of the full cycle is estimated at 269 50 years the 1989 loma prieta earthquake which is the culmination of the first subcycle in the present long term seismic cycle should have been predictable with an uncertainty of 2 years in time and 0 5 in magnitude although the specific location at loma prieta was not predictable by this technique if our model is correct and if the loma prieta earthquake is the culmination of a subcycle the san francisco bay region should be entering a relatively long 20 50 years period of seismic quiescence above magnitude 6 a great earthquake such as the 1906 san francisco event would appear to be more than a century in the future

active zone size versus activity a study of different seismicity patterns in the context of the prediction algorithm m8 a new precursory measure called active zone size azs based on the development of spatial correlations was recently introduced in the context of predicting large events in dynamical models of faults the new measure counts the fraction of the total seismic area which has exhibited earthquakes recently in each of the models tested azs was found to be more strongly correlated with an increase in the likelihood of a large event than the more conventional measure activity n which is defined to be the total number of earthquakes in this paper we report the first application of azs to seismicity catalogs we compare measurements of azs and n both individually and in the context of the intermediate term earthquake prediction algorithm m8 applied here specifically to data from the western united states to test the performance we replace functions in m8 which are based on n with similar functions based on azs when this is done at least on this limited data set the performance of ms is somewhat improved false alarm time is reduced and the landers earthquake is successfully predicted

real time test of the long range aftershock algorithm as a tool for mid term earthquake prediction in southern california result of the algorithm of earthquake prediction published in 1982 is examined in this paper the algorithm is based on the hypothesis of long range interaction between strong and moderate earthquakes in a region it has been applied to the prediction of earthquakes withm 6 4 in southern california for the time interval 1932 1979 the retrospective results were as follows 9 out of 10 strong earthquakes were predicted with average spatial accuracy of 58 km and average delay time the time interval between a strong earthquake and its best precursor 9 4 years varying from 0 8 to 27 9 years during the time interval following the period studied in that publication namely in 1980 1988 four earthquakes occurred in the region which had a magnitude ofm 6 4 at least in one of the catalogs caltech or noaa three earthquakes coalinga of may 1983 chalfant valley of july 1985 and superstition hills of november 1987 were successfully predicted by the published algorithm

testing earthquake prediction algorithms statistically significant advance prediction of the largest earthquakes in the circum pacific 1992 1997 abstract algorithms m8 and msc i e the mendocino scenario were used in a real time intermediate term research prediction of the strongest earthquakes in the circum pacific seismic belt predictions are made by m8 first then the areas of alarm are reduced by msc at the cost that some earthquakes are missed in the second approximation of prediction in 1992 1997 five earthquakes of magnitude 8 and above occurred in the test area all of them were predicted by m8 and msc identified correctly the locations of four of them the space time volume of the alarms is 36 and 18 correspondingly when estimated with a normalized product measure of empirical distribution of epicenters and uniform time the statistical significance of the achieved results is beyond 99 both for m8 and msc for magnitude 7 5 10 out of 19 earthquakes were predicted by m8 in 40 and five were predicted by m8 msc in 13 of the total volume considered this implies a significance level of 81 for m8 and 92 for m8 msc the lower significance levels might result from a global change in seismic regime in 1993 1996 when the rate of the largest events has doubled and all of them become exclusively normal or reversed faults the predictions are fully reproducible the algorithms m8 and msc in complete formal definitions were published before we started our experiment keilis borok v i kossobokov v g 1990 premonitory activation of seismic flow algorithm m8 phys earth and planet inter 61 73 83 kossobokov v g keilis borok v i smith s w 1990 localization of intermediate term earthquake prediction j geophys res 95 19763 19772 healy j h kossobokov v g dewey j w 1992 a test to evaluate the earthquake prediction algorithm m8 u s geol surv ofr 92 401 m8 is available from the iaspei software library healy j h keilis borok v i lee w h k eds 1997 algorithms for earthquake statistics and prediction vol 6 iaspei software library