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

1 fβ fluctuations and self similarity in earthquake dynamics observational evidences in southern italy abstract recently it has been determined that many statistical features of earthquakes are scale invariant with universal values for exponents the analysis of scaling laws has led to the development of a wide variety of physical models of seismogenesis involving nonlinear dynamics and it can be used to better characterize the seismicity pattern in this work the presence of scale invariance properties in the seismicity of a selected area of the southern appennine chain is revealed 1 f fluctuations are detected from the analysis of earthquake sequences using the counting statistics and at the spatial scale a self similar structure in the epicentre aggregate is determined by the estimation of its fractal dimension finally correlations between temporal exponent fractal dimension and b value variations are described

statistical physics seismogenesis and seismic hazard the scaling properties of earthquake populations show remarkable similarities to those observed at or near the critical point of other composite systems in statistical physics this has led to the development of a variety of different physical models of seismogenesis as a critical phenomenon involving locally nonlinear dynamics with simplified rheologies exhibiting instability or avalanche type behavior in a material composed of a large number of discrete elements in particular it has been suggested that earthquakes are an example of a self organized critical phenomenon analogous to a sandpile that spontaneously evolves to a critical angle of repose in response to the steady supply of new grains at the summit in this stationary state of marginal stability the distribution of avalanche energies is a power law equivalent to the gutenberg richter frequency magnitude law and the behavior is relatively insensitive to the details of the dynamics here we review the results of some of the composite physical models that have been developed to simulate seismogenesis on different scales during 1 dynamic slip on a preexisting fault 2 fault growth and 3 fault nucleation the individual physical models share some generic features such as a dynamic energy flux applied by tectonic loading at a constant strain rate strong local interactions and fluctuations generated either dynamically or by fixed material heterogeneity but they differ significantly in the details of the assumed dynamics and in the methods of numerical solution however all exhibit critical or near critical behavior with behavior quantitatively consistent with many of the observed fractal or multifractal scaling laws of brittle faulting and earthquakes including the gutenberg richter law some of the results are sensitive to the details of the dynamics and hence are not strict examples of self organized criticality nevertheless the results of these different physical models share some generic statistical properties similar to the universal behavior seen in a wide variety of critical phenomena with significant implications for practical problems in probabilistic seismic hazard evaluation in particular the notion of self organized criticality or near criticality gives a scientific rationale for the a priori assumption of stationarity used as a first step in the prediction of the future level of hazard the gutenberg richter law a power law in energy or seismic moment is found to apply only within a finite scale range both in model and natural seismicity accordingly the frequency magnitude distribution can be generalized to a gamma distribution in energy or seismic moment a power law with an exponential tail this allows extrapolations of the frequency magnitude distribution and the maximum credible magnitude to be constrained by observed seismic or tectonic moment release rates the answers to other questions raised are less clear for example the effect of the a priori assumption of a poisson process in a system with strong local interactions and the impact of zoning a potentially multifractal distribution of epicentres with smooth polygons the results of some models show premonitory patterns of seismicity which could in principle be used as mainshock precursors however there remains no consensus on both theoretical and practical grounds on the possibility or otherwise of reliable intermediate term earthquake prediction

a review of earthquake statistics fault and seismicity based models etas and bass there are two fundamentally different approaches to assessing the probabilistic risk of earthquake occurrence the first is fault based the statistical occurrence of earthquakes is determined for mapped faults the applicable models are renewal models in that a tectonic loading of faults is included the second approach is seismicity based the risk of future earthquakes is based on the past seismicity in the region these are also known as cluster models an example of a cluster model is the epidemic type aftershock sequence etas model in this paper we discuss an alternative branching aftershock sequence bass model in the bass model an initial or seed earthquake is specified the subsequent earthquakes are obtained from statistical distributions of magnitude time and location the magnitude scaling is based on a combination of the gutenberg richter scaling relation and the modified bath s law for the scaling relation of aftershock magnitudes relative to the magnitude of the main earthquake omori s law specifies the distribution of earthquake times and a modified form of omori s law specifies the distribution of earthquake locations unlike the etas model the bass model is fully self similar and is not sensitive to the low magnitude cutoff

nonlinear processes in earthquake foci the results of laboratory experiments on biaxially compressed physical models of a seismic source are presented discussed and interpreted in terms of nonlinear dynamics the relation is shown between the degree of seismic pulse coherency expressed through the amplitude frequency spectra development and energy or magnitude in a series of model experiments it has been ascertained that the degree of radiated waves coherency plays a more important role concerning the seismic energy release than the size radius of the seismic source

intermediate term prediction of occurrence times of strong earthquakes pattern recognition procedures for infrequent events are adapted to the problem of identifying patterns of clustering of small and intermediate scale seismicity before large earthquakes identification procedures derived from analysis of large california and nevada earthquakes yield a high success rate when applied to other parts of the world

mid continental earthquakes spatiotemporal occurrences causes and hazards abstract large earthquakes in north china australia northwestern europe central and eastern united states and other mid continents show complex spatiotemporal patterns that do not fit existing earthquake models individual faults or fault zones tend to fall into long term thousands of years or longer dormancy after a cluster of ruptures whereas large earthquakes seem to roam between widespread faults these behaviors are characteristic of complex dynamic systems of interacting faults in such systems widespread faults collectively accommodate slow tectonic loading and a major fault rupture both transfers stress to the neighboring faults and perturbs loading conditions on distant faults because of the slow tectonic loading local stress variations from fault interaction or nontectonic processes or changes of fault strength could trigger mid continental earthquakes the precise spatiotemporal occurrence of large mid continental earthquakes may be unknowable an intrinsic limitation of complex dynamic systems but their qualitative system behavior may be understood by a system approach this approach would render some commonly used concepts such as seismic cycles recurrence intervals characteristic earthquakes and seismic gaps inadequate or irrelevant in mid continents and calls for rethinking of the probability estimates based on these concepts it requires a better understanding of fault interactions on multiple spatial and temporal scales rather than focusing solely on the balance of tectonic loading and yield strength of individual faults or fault segments it also indicates the need for paleoseismic and geodetic studies extending beyond areas where recent large earthquakes occurred and for hazard assessments to reduce the biasing influence of the most recent large earthquakes that tend to dominate the short and incomplete earthquake records

a 2 d model for tilt and strain fields associated to earthquakes in crustal block structures abstract a 2 d model for slow crustal movements including tilt and strain anomalies before earthquakes as well as shape and time lag of each preseismic anomaly with respect to the time of origin of the corresponding earthquake is proposed the model represents a numerical study to evaluate the behavior of a series of crustal rigid blocks separated by narrow fault zones filled with viscoelastic material rheology of the fault material is described by constitutive equations of standard linear solid vertical displacement and rotation of the blocks result from the vertical uplift of one central block due to a vertical force displacements and tilts of blocks are computed from a system of linear differential equations which are solved numerically the main characteristic feature of the model is that the viscoelastic parameters of the fault zone where fracture occurs at the boundary of the rising block may change in time simulating the earthquake preparation numerical modelling shows that tilt behavior at successive blocks reveals anomalies which are similar in shape to the observed ones the anomalies are of opposite signs in adjacent blocks and show a time lag with distance from the fracturing zone

time variation of parameters related to the accelerating preshock crustal deformation in the aegean area the time variation of two parameters related to accelerating seismic deformation before strong earthquakes in the aegean area is examined the first is the b parameter of the gutenberg richter relation and the second is the curvature parameter c which is a measure of deviation of the accelerating preshock deformation from a linear time variation of this deformation following two different procedures it was found that the b value exhibits a decreasing trend prior to the oncoming earthquake in agreement with the results of laboratory experiments and other independent observations c values also show a decreasing trend before main shocks these results indicate that such time variations of these parameters can be considered as precursory phenomena of ensuing strong earthquakes

quantitative modeling of the lithosphere dynamics earthquakes and seismic hazard abstract understanding of lithosphere dynamics tectonic stress localization earthquake occurrences and seismic hazards has significantly advanced during the last decades meanwhile despite the major advancements in geophysical sciences yet we do not see a decline in earthquake disaster impacts and losses although earthquake disasters are mainly associated with significant vulnerability of society comprehensive seismic hazards assessments and earthquake forecasting could contribute to preventive measures aimed to reduce impacts of earthquakes modeling of lithosphere dynamics and earthquake simulations coupled with a seismic hazard analysis can provide a better assessment of potential ground shaking due to earthquakes here we present a block and fault dynamics bafd model which simulates earthquakes due to lithosphere dynamics and allows for studying the influence of fault network properties and regional movements on seismic patterns the model s performance is analyzed in terms of reproduction of basic features of the observed seismicity such as the frequency magnitude relationship clustering of earthquakes occurrences of large events fault slip rates and earthquake mechanisms several studies related to the application of the bafd model to the following earthquake prone regions are reviewed the southeastern carpathians caucasus the western india tibet himalaya and the sunda arc we examine then a new approach to seismic hazard analysis which is based on instrumentally recorded historical and bafd simulated earthquakes and analyze how earthquake modeling can assist in hazard assessment finally we discuss perspectives in modeling of earthquake occurrences and improvements in hazard assessment

diagnosis of time of increased probability of strong earthquakes in the jordan dead sea rift zone abstract we have explored the possibility of intermediate term earthquake prediction in the jordan dead sea rift region using the cn algorithm keilis borok et al 1988 this algorithm is designed to identify the time of increased probability tip of the occurrence of strong earthquakes defined by the conditionm m0 where m is the earthquake magnitude and m0 is a numerical threshold chosen for the considered region the area under diagnosis includes israel most of lebanon and the eastern parts of jordan and syria three strong earthquakes defined by the condition m0 5 occurred in this area during the period july 1964 june 1990 by applying the cn algorithm with unchanged standard parameters we found that two of the strong earthquakes were within the range of corresponding tip intervals these intervals extend far beyond the time of the occurrence of the strong earthquakes and represent about 40 5 of the total time however the tip duration is considerably reduced to about 12 9 of the total time when the threshold of the tip termination rule is slightly changed although this a posteriori change violates the formal standard application of the cn algorithm the results seem to be encouraging since false alarms did not appear at random and the excessive tip duration has a simple and rather obvious explanation however it seems that the conditions for the determination of tips in the cn algorithm should be modified accordingly

reverse tracing of short term earthquake precursors abstract we introduce a new approach to short term earthquake prediction named reverse tracing of precursors rtp since it considers precursors in reverse order of their appearance first we detect the candidates for the short term precursors in our case these are newly introduced chains of earthquakes reflecting the rise of an earthquake correlation range then we consider each chain one by one checking whether it was preceded by an intermediate term precursor in its vicinity if yes we regard this chain as a precursor in prediction it would start a short term alarm the chain indicates the narrow area of possibly complex shape where an intermediate term precursor should be looked for this makes possible to detect precursors undetectable by the direct analysis rtp can best be described on an example of its application we describe retrospective prediction of two prominent californian earthquakes landers 1992 m 7 6 and hector mine 1999 m 7 3 and suggest a hypothetical prediction algorithm this paper descripes the rtp methodology which has potentially important applications to many other data and to prediction of other critical phenomena besides earthquakes in particular it might vindicate some short term precursors previously rejected as giving too many false alarms validation of the algorithm per se requires its application in different regions with a substantial number of strong earthquakes first and positive retrospective results are obtained for 21 more strong earthquakes in california m 6 4 japan m 7 0 and the eastern mediterranean m 6 5 these results are described elsewhere the final validation requires as always prediction in advance for which this study sets up a base we have the first case of a precursory chain reported in advance of a subsequent strong earthquake tokachi oki japan 25 september 2003 m 8 1 possible mechanisms underlying rtp are outlined

the lithosphere of the earth as a nonlinear system with implications for earthquake prediction the lithosphere of the earth can be viewed as a hierarchy of volumes from tectonic plates to grains of rock their relative movement against the forces of friction and cohesion is realized to a large extent through earthquakes the movement is controlled by a wide variety of independent processes concentrated in the thin boundary zones between the volumes a boundary zone has a similar hierarchical structure consisting of volumes separated by boundary zones etc altogether these processes transform the lithosphere into a large nonlinear system featuring instability and deterministic chaos from this background some integral grossly averaged empirical regularities emerge indicating a wide range of similarity collective behavior and the possibility of intermediate term earthquake prediction

pattern informatics and its application for optimal forecasting of large earthquakes in japan pattern informatics pi technique can be used to detect precursory seismic activation or quiescence and make an earthquake forecast here we apply the pi method for optimal forecasting of large earthquakes in japan using the data catalogue maintained by the japan meteorological agency the pi method is tested to forecast large magnitude m 5 earthquakes spanning the time period 1995 2004 in the kobe region visual inspection and statistical testing show that the optimized pi method has forecasting skill relative to the seismic intensity data often used as a standard null hypothesis moreover we find in a retrospective forecast that the 1995 kobe earthquake m 7 2 falls in a seismically anomalous area another approach to test the forecasting algorithm is to create a future potential map for large m 5 earthquake events this is illustrated using the kobe and tokyo regions for the forecast period 2000 2009 based on the resulting kobe map we point out several forecasted areas the epicentral area of the 1995 kobe earthquake the wakayama area the mie area and the aichi area the tokyo forecast map was created prior to the occurrence of the oct 23 2004 niigata earthquake m 6 8 and the principal aftershocks with 5 0 m we find that these events were close to in a forecasted area on the tokyo map the pi technique for regional seismicity observation substantiates an example showing considerable promise as an intermediate term earthquake forecasting in japan

palynological implication of holocene vegetation and environment in pyeongtaek wetland korea abstract vegetational and depositional environmental changes were interpreted from a trench in ca 10 000 cal bp sediments in the pyeongtaek wetland korea based on palynomorph and grain size analysis from ca 10 400 8000 cal bp cool dry temperate conditions encouraged quercus dominated deciduous broadleaved forest with conifers and cool tolerant birch prevailing on hills and in mountainous areas as postglacial warming began halophytic chenopodiaceae pollen and marine dinoflagellates indicate the depositional environment was an intertidal flat conditions became warm and wet between ca 8000 and ca 6000 cal bp areas still contained quercus dominated deciduous broadleaved forest but with decreased conifers and cool tolerant birch the absence of marine dinoflagellates and abundant meso to hypersaline salt marshes of gramineae with a later increase of mesosaline cyperaceae marshes indicate a transition from intertidal flat to freshwater swamp from ca 6000 to ca 4500 cal bp quercus dominated forests were replaced by mixed conifer deciduous broadleaved forests under climatic deterioration aquatic genera and freshwater algae indicate that the study area completely changed to freshwater swamp the directional sequence in relative abundance of taxa maximum percentage of pollen of chenopodiaceae followed by gramineae cyperaceae and aquatics suggests a gradational pattern indicative of marked environmental clines typical of intertidal habitats

comparative performance of time invariant long range and short range forecasting models on the earthquake catalogue of greece 1 time invariant long range and short range forecasting models were fitted to the earthquake catalogue of greece for magnitudes 4 0 and greater to optimize their ability to forecast events of magnitude 6 0 and greater in the period 1966 1980 the models considered were stationary spatially uniform and spatially varying poisson models a long range forecasting model based on the precursory scale increase phenomenon with every earthquake regarded as a precursor according to scale and epidemic type short range forecasting models with spatially uniform and spatially varying spontaneous seismicity each of the models was then applied to the catalogue for 1981 2002 and their forecasting performance was compared using the log likelihood statistic the long range forecasting model performed substantially better than the time invariant models and the short range forecasting models performed substantially better again the results show that the information value to be gained from modeling temporal and spatial variation of earthquake occurrence rate at both long and short range is much greater than can be gained from modeling spatial variation alone

application of a modified pattern informatics method to forecasting the locations of future large earthquakes in the central japan we propose a modification of the pattern informatics pi method that has been developed for forecasting the locations of future large earthquakes this forecast is based on analyzing the space time patterns of past earthquakes to find possible locations where future large earthquakes are expected to occur a characteristic of our modification is that the effect of errors in the locations of past earthquakes on the output forecast is reduced we apply the modified and original methods to seismicity in the central part of japan and compared the forecast performances we also invoke the relative intensity ri of seismic activity and randomized catalogs to constitute null hypotheses we do statistical tests using the molchan and relative operating characteristic roc diagrams and the log likelihoods and show that the forecast for using the modified pi method is generally better than the competing original pi forecast and the forecasts from the null hypotheses using the bootstrap technique with monte carlo simulations we further confirm that earthquake sequences simulated based on the modified pi forecast can be statistically the same as the real earthquake sequence so that the forecast is acceptable the main and innovative science in this paper is the modification of the pi method and the demonstration of its applicability showing a considerable promise as an intermediate term earthquake forecasting tool

qualitative chaos in geomorphic systems with an example from wetland response to sea level rise the spatial and temporal complexity of earth surface processes and landforms and the presence of deterministic chaos in many fundamental physical processes provide reasons to suspect chaos in geomorphic systems a method is presented to assess the likelihood of chaotic behavior in a geomorphic system the method requires identification of the fundamental system components their positive negative or negligible influences on each other and the relative strength or magnitudes of these links based on this information the method can classify geomorphic systems as stable and nonchaotic unstable and potentially chaotic or unstable and generally chaotic positive self enhancing feedback is a key diagnostic of the likelihood of chaotic behavior a sample application of the method to the problem of coastal marsh response to sea level rise is provided which shows the marsh to be unstable if changes in vegetation cover are partly dependent on vegetation density the system is generally chaotic if marsh veg

non linear dynamics of the lithosphere and intermediate term earthquake prediction abstract the lithosphere of the earth is structured as a hierarchical system of volumes of different sizes from about 10 tectonic plates to about 10 25 grains of rock their relative movement against the forces of friction and cohesion is realized to a large extent through earthquakes the movement is controlled by a wide variety of independent processes concentrated in the thin boundary zones between the volumes the boundary zone has a similar hierarchical structure consisting of volumes separated by boundary zones etc altogether this hierarchy of volumes and multitude of processes compose the lithosphere into a large non linear complex system upon coarse graining the integral mesoscale empirical regularities emerge indicating a wide range of similarity collective behavior and the possibility of earthquake prediction this approach led to new paradigms in the dynamics of the lithosphere and on the practical side created a capacity to predict from 70 to 90 of large earthquakes with alarms occupying 10 20 of the time space considered such predictions may be used to undertake earthquake preparedness measures which would prevent a considerable part of the damage although far from the total damage the methodology linking prediction with preparedness was developed it may help a disaster management authority to choose the preparedness measures allowing for the currently realistic accuracy of predictions a large scale experiment in advance prediction of large earthquakes worldwide has been launched to test the prediction algorithms the test is unprecedented in rigor and coverage the forecasts are communicated with due discretion to several dozen leading scientists and administrators in many countries among already predicted earthquakes are all the last eight great ones with magnitude 8 and more the major drawback is the rate of false alarms the possibility is outlined to develop a new generation of prediction methods with fivefold increase in accuracy and the transition to short term prediction the links with prediction of geotechnical and engineering disasters are established scenarios of transitions to a large earthquake happen to share some features with a broader class of catastrophes this experience now opens as yet untapped possibilities for reduction of technological disasters

precursory seismic activation and critical point phenomena in this paper we relate the behavior of seismicity prior to a characteristic earthquake to the excitation in proximity to a spinodal instability we illustrate the spinodal instability as the upper limit of superheated water prior to a steam explosion we draw an analogy between the steam explosion and a characteristic earthquake and show that the power law activation associated with the spinodal instability is essentially identical to the power law increase in benioff strain observed prior to characteristic earthquakes we find that theory and actual data give very similar results

implications of a statistical physics approach for earthquake hazard assessment and forecasting there is accumulating evidence that distributed seismicity is a problem in statistical physics seismicity is taken to be a type example of self organized criticality this association has important implications regarding earthquake hazard assessment and forecasting a characteristic of a thermodynamic system is that it exhibits a background noise that is self organized in the case of a dilute gas this self organization is the maxwell boltzmann distribution of molecular velocities in seismicity it is the gutenberg richter frequency magnitude scaling this scaling is fractal observations favor the hypothesis that smaller earthquakes in moderate sized regions occur at rates that are only weakly dependent on time thus the rate of occurrence of smaller earthquakes can be extrapolated to assess the hazard of larger earthquakes in a region we obtain the rate of occurrence of earthquakes with m 4 in 1 1 areas from the neic catalog using only this data we produce global maps of the seismic hazard observations also favor the hypothesis that the stress level at which an earthquake occurs is a second order critical point as a critical point is approached correlations extend over increasingly larger distances in terms of seismicity the approach to a critical point is associated with an increase in the rate of occurrence of intermediate sized earthquakes prior to a large earthquake this precursory activation has been shown to exhibit power law scaling and to occur over a region about ten times larger than the rupture length of the large earthquake analyses of the spinoidal behavior associated with second order critical points predict the power law increase in seismic activity prior to a characteristic earthquake this precursory activation provides the basis for intermediate range earthquake forecasting

characterizing aftershock sequences of the recent strong earthquakes in central italy the recent strong earthquakes in central italy allow for a comparative analysis of their aftershocks from the viewpoint of the unified scaling law for earthquakes usle which generalizes the gutenberg richter relationship making use of naturally fractal distribution of earthquake sources of different size in a seismic region in particular we consider aftershocks as a sequence of avalanches in self organized system of blocks and faults of the earth lithosphere each aftershock series characterized with the distribution of the usle control parameter we found the existence in a long term of different intermittent levels of rather steady seismic activity characterized with a near constant value of which switch in mid term at times of transition associated with catastrophic events on such a transition seismic activity may follow different scenarios with inter event time scaling of different kind including constant logarithmic power law exponential rise decay or a mixture of those as observed in the case of the ongoing one associated with the three strong earthquakes in 2016 evidently our results do not support the presence of universality of seismic energy release while providing constraints on modelling seismic sequences for earthquake physicists and supplying decision makers with information for improving local seismic hazard assessments

linear and nonlinear dynamics in electrical precursory time series implications for earthquake prediction abstract the time dynamics of geoelectrical precursory time series has been investigated using autoregressive models the approach used here allows us to obtain information on the geophysical system producing the electrical phenomena in seismic active areas when the only information about the time series comes from the time series themselves it is based on two forecasting approaches the global autoregressive approximation and the local autoregressive approximation the first approach views the data as a realization of a linear stochastic process whereas the second approach considers the data points as the results of a deterministic process supposedly nonlinear the comparison of the predictive skills of the two techniques is a strong test to distinguish between low dimensional chaos and random dynamics our findings give us insight in the inner dynamics of the geophysical process under study an estimate of the number of degrees of freedom of the dynamical system governing the electrical phenomena is obtained the stochastic nature of the electrical precursory signals has been highlighted and the possible implications for the earthquake prediction problem are discussed the processed time series are geoelectrical measurements recorded by an automatic station located in tito southern italy which is one of the most seismic areas of the mediterranean region we found that the global linear approach is superior to the local one and the physical system governing the phenomena of electrical nature is characterized by a large number of degrees of freedom the results are confirmed by the presence of rich scaling properties in the power spectra of the processed electrical signals

statistical physics approach to understanding the multiscale dynamics of earthquake fault systems 1 earthquakes and the faults upon which they occur interact over a wide range of spatial and temporal scales in addition many aspects of regional seismicity appear to be stochastic both in space and time however within this complexity there is considerable self organization we argue that the occurrence of earthquakes is a problem that can be attacked using the fundamentals of statistical physics concepts of statistical physics associated with phase changes and critical points have been successfully applied to a variety of cellular automata models examples include sandpile models forest fire models and particularly slider block models these models exhibit avalanche behavior very similar to observed seismicity a fundamental question is whether variations in seismicity can be used to successfully forecast the occurrence of earthquakes several attempts have been made to utilize precursory seismic activation and quiescence to make earthquake forecasts some of which show promise

nonlinear dynamics of crustal blocks and faults and earthquake occurrences in the transcaucasian region abstract the caucasus is a part of ongoing collision of the arabian and eurasian plates where moderate to strong earthquakes caused significant losses of lives and livelihood in the past to better understand seismic hazard in the region we develop a model of block and fault dynamics for transcaucasia the largest part of the caucasus to the south of the greater caucasus mountains to simulate regional earthquakes the model structure is developed by employing the results of the morphostructural analysis to delineate crustal blocks and the geodetic observations on crustal movements in the region the model incorporates a nonlinear rate dependent slip of the faults separating the blocks a set of numerical experiments has been performed to address the following questions i where strong earthquakes occur and what their reoccurrence time is ii how rigid crustal blocks react to the arabian plate push and to movements of the ductile part of the crust in transcaucasia and iii whether the fault slip rates and the block displacements in the model correlate with observed gps velocities the model results confirm that the contemporary crustal dynamics and seismicity pattern in transcaucasia are determined by the north northeastern motion of the arabian plate relative to eurasia and by the movement of the ductile crust underlying the rigid crustal blocks variations in the rheological properties of the fault zones and or of the ductile crust influence the pattern of seismicity the number and maximum magnitude of synthetic earthquakes change with the variations in the movements of the crustal blocks and in the rheological properties of the lower crust and the fault zones the model results can be used in comprehensive seismic hazard assessment of the caucasus region based on instrumentally observed historical and synthetic seismicity

continental drift and a theory of convection early geologists considered that the earth s surface is rigid and unchanging they assumed that the whole earth is static except for enough sub surface contraction to build mountains after seismology developed most geophysicists agreed a few scientists notably wegener favoured a more mobile earth about 1965 fresh evidence showed that both theories were too simple this evidence explained why neither theory had been able to relate the whole earth s behaviour to laws of physics hence different aspects of geology had only been solved separately which had fragmented earth science this paper proposes a compromise it is that the rigid lithosphere fractures according to navier s law of brittle failure which explains the properties and provides methods for classifying faults plate boundaries and mountains and that the ductile mantle convects by laws of fluid flow in patterns partly controlled by lithospheric fractures these dual interacting influences explain tectonic behaviour the pattern of currents is hidden at any one time upwelling beneath continents only affects a few limited areas today some are in southwestern united states central asia botswana antarctica and rifts in east africa europe and siberia nevertheless recognition of upwelling currents may revolutionize geology because their cumulative effects have been great and neglected

love rayleigh wave incompatibility and possible deep upper mantle anisotropy in the iberian peninsula love and rayleigh wave phase velocities are analyzed with the goal of retrieving information about the anisotropic structure of the iberian lithosphere the cross correlation method is used to measure the interstation phase velocities between diverse stations of the iliha network at periods between 20 and 120 s despite the 2 d structure of the network the love wave data are too few to enable an analysis of phase velocity azimuthal variations azimuthal averages of love and rayleigh wave phase velocities are calculated and inverted both in terms of isotropic and anisotropic structures realistic isotropic models explain the rayleigh wave and short period love wave phase velocities therefore no significant anisotropy needs to be introduced in the crust and down to 100 km depth in the upper mantle to explain our data a discrepancy is observed only at long periods where the data are less reliable love wave data at periods between 80 and 120 s remain 0 15 km s faster than predicted by isotropic models explaining the long period rayleigh wave data possibilities of biases in the measurements due to interferences with higher modes are examined but seem unlikely a transversely isotropic model with 8 of s wave velocity anisotropy in the upper mantle at depths larger than 100 km can explain the whole set of data in terms of a classical model of mantle anisotropy this corresponds to 100 of the crystals perfectly oriented in the horizontal plane in a pyrolitic mantle this is a rather extreme model which predicts at time delay between 0 and 2 seconds for split sks

testing an earthquake prediction algorithm the 2016 new zealand and chile earthquakes the 13 november 2016 m7 8 54 km nne of amberley new zealand and the 25 december 2016 m7 6 42 km sw of puerto quellon chile earthquakes happened outside the area of the on going real time global testing of the intermediate term middle range earthquake prediction algorithm m8 accepted in 1992 for the m7 5 range naturally over the past two decades the level of registration of earthquakes worldwide has grown significantly and by now is sufficient for diagnosis of times of increased probability tips by the m8 algorithm on the entire territory of new zealand and southern chile as far as below 40 s the mid 2016 update of the m8 predictions determines tips in the additional circles of investigation cis where the two earthquakes have happened thus after 50 semiannual updates in the real time prediction mode we 1 confirm statistically approved high confidence of the m8 msc predictions and 2 conclude a possibility of expanding the territory of the global test of the algorithms m8 and msc in an apparently necessary revision of the 1992 settings

a cellular automata slider block model for earthquakes ii demonstration of self organized criticality for a 2 d system summary it has been suggested that distributed seismicity is an example of self organized criticality if this is the case the earth s crust in an active tectonic zone is in a near critical state and faults can interact over large distances observed seismicity and earthquake statistics are consequences of the dynamical interaction of seismic faulting over a wide range of scales we address this problem by considering a two dimensional array of slider blocks with static dynamic friction the twodimensional system is treated as a cellular automaton such that only one slider block is allowed to slip at a given time and interacts only with its nearest neighbours through connecting springs because of this treatment the amount of slip for each failed block can be obtained analytically and the system is deterministic with no stochastic inputs or spatial heterogeneities in many cases the slip of one block induces the slip of adjacent blocks the size of an event is specified by the number of blocks that participate in the event the number of small events with a specified size has a power law dependence on the size with a power close to 1 36 the distributions of normalized recurrence times for most events are close to a poisson process and gradually deviate towards periodicity for large events the recurrence time statistics are generally insensitive to parameter variations large events may occur at stress levels considerably lower than the failure strength of an individual block and the stress drops associated with large events are generally small this may provide an explanation for observed low stress levels in tectonically active

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

seismic hazard from instrumentally recorded historical and simulated earthquakes application to the tibet himalayan region abstract we present a new approach to assessment of regional seismic hazard which accounts for observed instrumentally recorded and historic earthquakes as well as for seismic events simulated for a significantly longer period of time than that of observations we apply this approach to probabilistic seismic hazard analysis psha for the tibet himalayan region the large magnitude synthetic events which are consistent with the geophysical and geodetic data together with the observed earthquakes are employed for the monte carlo psha earthquake scenarios for hazard assessment are generated stochastically to sample the magnitude and spatial distribution of seismicity as well as the distribution of ground motion for each seismic event the peak ground acceleration values which are estimated for the return period of 475 yr show that the hazard level associated with large events in the tibet himalayan region significantly increases if the long record of simulated seismicity is considered in the psha the magnitude and the source location of the 2008 wenchuan m 7 9 earthquake are among the range of those described by the seismic source model accepted in our analysis we analyze the relationship between the ground motion data obtained in the earthquake s epicentral area and the obtained psha estimations using a deaggregation technique the proposed approach provides a better understanding of ground shaking due to possible large magnitude events and could be useful for risk assessment earthquake engineering purposes and emergency planning

rifting attractor structures in the baikal rift system location and effects abstract the current geodynamics and tectonophysics of the baikal rift system brs as recorded in lithospheric stress and strain are discussed in the context of self organization of nonlinear dissipative dynamic systems and nonlinear media the regional strain field inferred from instrumental seismic moment and fault radius data for almost 70 000 m lh 2 0 events of 1968 through 1994 shows a complex pattern with zones of high strain anisotropy in the central part and both flanks of the rift system the south baikal hovsgol and muya rift basins respectively the three zones of local strain anisotropy highs coincide with domains of predominantly vertical stress where earthquakes of different magnitudes are mostly of normal slip geometry pulse like reversals of principal stresses in the high strain domains appear to be nonlinear responses of the system to subcrustal processes in this respect the brs lithosphere is interpreted in terms of the self organization theory as a geological dissipative system correspondingly the domains of high strain anisotropy and stress change called rifting attractor structures ras are the driving forces of its evolution the location and nonlinear dynamics of the rifting attractors have controlled lithospheric stress and strain of the rift system over the period of observations and the same scenario may have been valid also in the mesozoic cenozoic rifting history the suggested model of a positive feedback fire like evolution of nonlinear dynamical systems with rifting attractors opens a new perspective on the current geodynamics and tectonophysics of the baikal rift system

global scale analysis of seismic activity prior to 2004 sumatra andaman mega earthquake abstract following our experience in intermediate term monitoring of seismicity before large earthquakes worldwide and in some regions we apply a similar approach to the analysis of seismicity on global scale several decades before the december 26 2004 sumatra andaman mega earthquake the earth lithosphere is being considered as a single whole representing the ultimate level of the complex earth s hierarchy the study brings up the following questions are there any anomalies of the global seismicity behaviour observed in advance of the mega earthquake do these anomalies correspond to the global scale seismic patterns similar to those detected on the regional scale before great major and strong events in other words does the earth lithosphere considered as a single whole show up an approach of the mega earthquake in the way typical for events on the smaller levels of hierarchy the results of our investigation favour the positive answer to the questions specifically we found that during the decade before the sumatra andaman mega earthquake the earth lithosphere reveals at least in intermediate term scale classical symptoms of instability which can be depicted by known precursory seismic patterns these are i transformation of frequency magnitude distribution ii change in the rate of seismic activity and iii depth redistribution of activity moreover changes of dependencies between magnitudes of different types are detected at the same time the observed global scale patterns of collective behaviour of seismicity may indicate the state of criticality of the earth lithosphere before the sumatra andaman mega earthquake

a nonlinear dynamical model of landslide evolution a nonlinear dynamical model for the evolution of landslide is proposed the parameters of this model are obtained through an improved iterative algorithm of inversion developed in the paper based on the nonlinear dynamical model and nonlinear dynamical systems nds theory the approaches to determining the lyapunov exponents the predictable timescale and the stability criterion of the evolutional state of landslide are given a case study of the xintan slope is presented to illustrate the capability and merit of the nonlinear dynamical model

an analysis of the process of acceleration of seismic energy emission in laboratory experiments on destruction of rocks and before strong earthquakes on kamchatka and in italy abstract the time to failure model is a technique in which a failure function is fitted to a time series of accumulated benioff strain before a large earthquake we analyze the relation of the time to failure model to the hypothesis of fractal structure of seismicity a power law failure function varnes 1989 bufe and varnes 1993 and its log periodic generalization sornette and sammis 1995 are discussed the results of application of the log periodic time to failure model to the analysis of the process of acceleration of seismic energy emission in the laboratory experiments on rock destruction and before strong earthquakes on kamchatka and in italy are presented

nonlinear dynamical systems in geomorphology revolution or evolution abstract geomorphic systems typically exhibit complex apparently random behaviors and patterns in both spatial and temporal domains this complexity can arise from the cumulative impacts of individual process response mechanisms which are far too numerous to be accounted for in individual detail or due to multiple controls over process response relationships which operate over a range of spatial and temporal scales stochastic complexity nonlinear dynamical systems nds theory which includes specific techniques and concepts such as chaos dissipative structures bifurcation and catastrophe theory and fractals shows that extreme complexity can also arise due to the nonlinear dynamics and couplings of relatively simple systems represented by relatively small equation systems deterministic complexity while emphasis in earth science has been largely on stochastic complexity geomorphologists have long recognized the presence of deterministic complexity as well recent developments in the study of nonlinear dynamical systems have implications for the ability to make reliable long term predictions and therefore applications of nds in geomorphology may be revolutionary to some extent however virtually all the basic conceptual underpinnings of nds theory can be mapped onto existing and even traditional theoretical concepts in geomorphology in this sense the use of nds concepts in understanding earth surface processes and landforms is evolutionary the link between traditional and nds based concepts is illustrated by analyzing a generalized geomorphic mass flux system it is shown that the system is in most cases unstable consistent with chaos or deterministic complexity however the three attractor states of the system correspond exactly to the states of aggradation degradation and steady state

earthquake failure sequences along a cellular fault zone in a three dimensional elastic solid containing asperity and nonasperity regions numerical simulations of earthquake failure sequences along a discrete cellular fault zone are performed for a three dimensional 3 d model representing approximately the central san andreas fault the model consists of an upper crust overlying a lower crust and mantle region together defining an elastic half space with a vertical half plane fault the fault contains a region where slip is calculated on a uniform grid of cells governed by a static kinetic friction law and regions where slip is prescribed so as to represent tectonic loading aseismic fault creep and adjacent great earthquakes the computational region models a 70 km long and 17 5 km deep section of the san andreas fault to the nw of the great 1857 rupture zone different distributions of stress drops on failing computational cells are used to model asperity parkfield asperity and nonasperity fault regions the model is inherently discrete and corresponds to a situation in which a characteristic size of geometric disorder within the fault i e cell size here a few hundreds of meters is much larger than the nucleation size of the order of tens of centimeters to tens of meters based on slip weakening or state evolution slip distances the computational grid is loaded by a constant plate motion imposed at the lower crust upper mantle and creeping fault regions and by a staircase slip history imposed at the 1857 and 1906 rupture zones stress transfer along and outside the fault due to the imposed loadings and failure episodes along the computational grid is calculated using 3 d elastic dislocation theory the resulting displacement field in the computational region is compatible with geodetic and seismological observations only when the asperity and nonasperity regions are characterized by significantly different average stress drops the frequency magnitude statistics of the simulated failure episodes are approximately self similar for small events with b 1 2 the b value of statistics based on rupture area ba is about 1 but are strongly enhanced with respect to self similarity for events larger than a critical size this is interpreted as a direct manifestation of our 3 d elastic stress transfer calculations beyond certain rupture area and potency seismic moment divided by rigidity release values the event is usually unstoppable and it continues to grow to a size limited by a characteristic model dimension this effect is not accounted for by cellular automata and block spring models in which the adopted simplified stress transfer laws fail to scale properly with increasing rupture size the simulations suggest that local maxima in observed frequency magnitude statistics correspond to dimensions of coherent brittle zones such as the width of the seismogenic layer or the length of a fault segment bounded by barriers the analysis indicates that a single cell size representing approximately a single scale of geometric disorder cannot induce self similarity in a 3 d elastic model over a broad range of magnitudes a representation of geometric disorder covering a range of scales may thus be required to generate a wide domain of self similar gutenberg richter statistics our simulations show a great diversity in the mode of failure of the parkfield asperity the earthquakes themselves define an irregular sequence of events the modeling like many other discrete fault models suggests that expectations for periodic parkfield earthquakes and or simple precursory patterns repeating from one event to the other are unrealistic

chaos fractals nonlinear phenomena in earth sciences many problems in geophysics can be solved using linear equations examples include seismic waves the earth s gravity and magnetic field and problems involving heat flow and elasticity however other problems are essentially non linear the classic example is fluid turbulence in the past twenty years major advances have been made in the understanding of nonlinear problems in the past four years many of these advances have been applied to geophysical problems

fluids migration and dynamics of a blocks and faults system abstract we explore the impact of fluids migrating through a fault network on the dynamics of lithosphere both on slow movements and seismicity for that purpose fluids in the fault zones are incorporated into modelling of blocks and faults systems which takes into account driving forces and the system s geometry simulations have been performed for two dimensional models an idealised brick wall structure and a coarse image of sinai subplate migrating fluids originating in different locations are considered as well as fluids trapped in closed pockets basic features of the modelled and observed seismicity are in good accord as shown by comparison with the earthquake catalog compiled by geophysical institute of israel

discrete characteristics of the aftershock sequence of the 2011 van earthquake an intraplate earthquake of magnitude mw 7 2 occurred on a ne sw trending blind oblique thrust fault in accretionary orogen the van region of eastern anatolia on october 23 2011 the aftershock seismicity in the van earthquake was not continuous but rather highly discrete this shed light on the chaotic nonuniformity of the event distribution and played key roles in determining the seismic coupling between the rupturing process and seismogeneity i analyzed the discrete statistical mechanics of the 2011 van mainshock aftershock sequence with an estimation of the non dimensional tuning parameters consisting of temporal clusters c and the random rn distribution of aftershocks range of size scales ross strength change ed temperature t p value of temporal decay material parameter r value seismic coupling and q value of aftershock distribution i also investigated the frequency size fs temporal t statistics and the sequential characteristics of aftershock dynamics using discrete approach and examined the discrete evolutionary periods of the van earthquake gutenberg richter gr distribution my study revealed that the fs and t statistical properties of aftershock sequence represent the gutenberg richter gr distribution clustered c in time and random rn poisson distribution respectively the overall statistical behavior of the aftershock sequence shows that the van earthquake originated in a discrete structural framework with high seismic coupling under highly variable faulting conditions my analyses relate this larger dip slip event to a discrete seismogenesis with two main components of complex fracturing and branching framework of the ruptured fault and dynamic strengthening and hardening behavior of the earthquake the results indicate two dynamic cases the first is associated with aperiodic nature of aftershock distribution indicating a time independent poissonian event the second is associated with variable slip model varying loading rates and high seismic coupling along the ruptured area this study concludes that the aperiodic statistical behavior of the van aftershock sequence is one of the results of the time independent poissonian seismic deformation in the 2011 van earthquake

aftershock sequences of the recent major earthquakes in new zealand the three clusters of the epicenters of the nine recent 1993 2018 earthquakes of magnitude 7 0 or larger in new zealand are located in three different tectonic environments of the australia pacific plate boundary including the southern part of the kermadec trench showing rapid westward subduction the oblique collision zone between the pacific plate and indo australian plate with the dominant alpine fault showing right lateral strike slip movement and the puysegur trench showing eastward oblique subduction from the viewpoint of the unified scaling law for earthquakes usle these regions are characterized by different levels of seismic rate a earthquake magnitude exponent b and fractal dimension of epicenter loci c the recent major earthquakes exemplify different scenarios of aftershock sequences in terms of either the dynamics of interevent time or the usle control parameter 10b 5 m lc where is the time interval between two successive earthquakes m is the magnitude of the second one and l is the distance between them we find the existence in the long term of different intermittent levels of rather steady seismic activity characterized by near constant values of mean which in the mid term switch between one another at times of critical transitions including those associated with all but one magnitude 7 0 or larger earthquake at such a transition seismic activity may follow different scenarios with interevent time scaling of different kinds evidently although these results based on analysis of an individual series do not support the presence of universality in seismic energy release they provide constraints on modeling realistic seismic sequences for earthquake physicists and supply decision makers with information for improving local seismic hazard assessments

plausibility of long distance electrotelluric precursors to earthquakes a systematic analysis of the plausibility of different classes of models which could account for low frequency precursory electrotelluric signals observable at large distances from a large earthquake is carried out first we consider linear models for which either a stationary electrical field is generated by a current dipole in the source volume or a static deformation field results from a precursory strain in the source volume linearly inducing a streaming potential effect near the electrode in the former case only the conjunction of very favorable circumstances may lead to an electrical field larger than 10 mv km at more than 100 km with the constraint that no anomaly exceeds a few volts per kilometer in the source area it indeed requires a powerful electrical dipole current 104 a length 1 km which might be produced by a streaming potential effect associated with the connection of nonhydrostatic fluid reservoirs pore pressure difference up to 100 mpa a two dimensional channeling of the electrical currents from the source to the electrode area which would result from high conductivity horizontal layers and finally a local amplification factor of typically 100 near the electrodes which might be produced by a narrowing of the conductive channel for an elastic long distance interaction an electric field of 10 mv km at a distance 10 times the source length 100 km away from a m 6 earthquake requires a precursory deformation larger than the coseismic deformation if no strong local amplification is considered alternatively nonlinear models are proposed and discussed assuming that the crust is stuffed with small scale local instabilities fractures and nonhydrostatic fluid reservoirs among which a number are close to their instability threshold these instabilities may follow their own evolutionary process inducing sporadic fluid flow and hence streaming potential effect in the vicinity of the electrodes without any relation to a remote tectonic activity however these instabilities may be sensitive to very small changes in the stress field and hence be triggered by the elastic precursory deformation of a remote seismic source this requires that the precursory deformation near the instability is at least larger than the tidal strain 10 7 this necessary condition is met at a distance of up to 10 times the source dimension when the precursory strain source is only 10 of the coseismic deformation provided that the strain source is double the size of the seismic fault itself this model could account for the absence of self potential anomalies related to the earthquake itself as a large proportion of the available instabilities could have been swept away by the precursory strain furthermore with such a model a precursory strain in the source area could induce a detectable change in the background seismic activity over a vast area which may give a new interpretation of the times of increased probability observations for short distances the triggering of fluid instabilities by strain perturbation and the associated streaming potential effect may well be a promising model for explaining low frequency electric and magnetic precursors

short term earthquake prediction by reverse analysis of lithosphere dynamics abstract short term earthquake prediction months in advance is an elusive goal of earth sciences of great importance for fundamental science and for disaster preparedness here we describe a methodology for short term prediction named rtp reverse tracing of precursors using this methodology the san simeon earthquake in central california magnitude 6 5 dec 22 2003 and the tokachi oki earthquake in northern japan magnitude 8 1 sept 25 2003 were predicted 6 and 7 months in advance respectively the physical basis of rtp can be summed up as follows an earthquake is generated by two interacting processes in a fault network an accumulation of energy that the earthquake will release and a rise of instability triggering this release energy is carried by the stress field instability is carried by the difference between the stress and strength fields both processes can be detected and characterized by premonitory patterns of seismicity or other relevant fields here we consider an ensemble of premonitory seismicity patterns rtp methodology is able to reconstruct these patterns by tracing their sequence backwards in time the principles of rtp are not specific to earthquakes and may be applicable to critical transitions in a wide class of hierarchical non linear systems

configurational entropy of critical earthquake populations we present an approach to describe the evolution of distributed seismicity by configurational entropy we demonstrate the detection of phase transitions in the sense of a critical point phenomenon in a 2d site percolation model and in temporal and spatial vicinity to the 1992 m7 3 landers earthquake in southern california our findings support the assumption of intermittent criticality in the earth s crust we also address the potential usefulness of the method for earthquake catalogue declustering

energetic balance in scaling organization of fracture tectonics abstract this paper presents a development of the seismicity model s o f t scaling organization and fracture tectonics we remain in the frame of this simple model which is based on an energy splitting combined with a renormalization group approach redistribution of energy over the entire considered domain after strong events was introduced in the previous model the present version displays some general features of real seismicity such as gutenberg richter law omori law of temporal decrease of the aftershock activity seismic cycle quiet periods with a background seismic activity periods of foreshock and aftershock activity this is shown by numerical experiments in both the single domain case and in the case of exchange of energy between several domains

search for direct empirical spatial correlation signatures of the critical triggering earthquake model summary we propose a new test of the critical earthquake model based on the hypothesis that precursory earthquakes are actors that create fluctuations in the stress field which exhibit an increasing correlation length as the critical large event becomes imminent our approach constitutes an attempt to build a more physically based time dependent indicator cumulative scalar stress function in the spirit of but improving on the cumulative benioff strain used in previous works documenting the phenomenon of accelerating seismicity using a simplified scalar space and time dependent viscoelastic green s function in a two layer model of the earth s lithosphere we compute spatiotemporal pseudo stress fluctuations induced by a series of events before four of the largest recent shocks in southern california through an appropriate spatial wavelet transform we then estimate the contribution of each event in the series to the correlation properties of the simplified pseudo stress field around the location of the mainshock at different scales this allows us to define a cumulative scalar pseudo stress function which reveals neither an acceleration of stress storage at the epicentre of the mainshock nor an increase of the spatial stress stress correlation length similar to those observed previously for the cumulative benioff strain the earthquakes we studied are thus either simple witnesses of a large scale tectonic organization or are simply unrelated and or the green s function describing interactions between earthquakes has a significantly longer range than predicted for standard viscoelastic media used here