Peter Shebalin

Russian Academy of Sciences | RAS · Institute of earthquake prediction theory and mathematical geophysics

The differential probability gain approach is used to estimate quantitatively the change in aftershock rate at various levels of ocean tides relative to the average rate model. An aftershock sequences are analyzed from two regions with high ocean tides, Kamchatka and New Zealand. The Omori-Utsu law is used to model the decay over time, hypothesizin...

S U M M A R Y Mechanisms of stress transfer and probabilistic models have been widely investigated to explain earthquake clustering features. However, these approaches are still far from being able to link individual events and to determine the number of earthquakes caused by a single event. An alternative approach based on proximity functions allo...

Continuing the series of publications on aftershock hazard assessment, we consider the problem of estimating the time interval after a strong earthquake that is prone to aftershocks which may pose an independent hazard. The distribution model of this quantity, which depends on three parameters of the Omori–Utsu law, is constructed. With the appropr...

The geometry of supposed coupling zones in the Kamchatka subduction zone is determined by the earthquake size distribution based on ealier revealed relationship between its shape and rate of inelastic deformations. In the areas of higher aseismic slip, a break of linearity in earthquake size distribution is observed owing to the deficit of large ea...

In this paper, we consider the problem of forecasting the magnitude of the strongest aftershock starting from a certain instant of time in the future. This problem is topical since the strong aftershocks that occur later against a background of less frequently repeating shocks are less expected and thus pose an independent hazard. At the same time,...

A new approach is proposed for determining earthquake hypocenters aimed at a more comprehensive characterization of its uncertainty and ambiguity. Application of the new approach to study the seismic focal subduction zones and volcanic seismicity is discussed by the example of the data of the Kamchatka Branch of the Geophysical Survey of the Russia...

The geometry of supposed coupling zones in the Kamchatka subduction zoneis determined by the earthquake size distribution based on earlier revealed relationship between its shape and rate of inelastic deformations. In the areas of higher aseismic slip, a break of linearity in earthquake size distribution is observed owing to the deficit of large ea...

This paper considers the global statistics of times of largest aftershocks relative to the times of the corresponding main shocks. A large data set was used to show that the time-dependent distribution of largest aftershocks obeys a power law distribution. This is analogous to the Omori law for the sequence of all after- shocks. It is also shown th...

The issue of whether tidal forces really affect seismicity has been raised many times in the literature. Nevertheless, even though there seems to be a kind of consensus that such effects do exist, no quantitative estimates are available to relate tide parameters to changes in the level of seismic activity. Such estimation for aftershocks of large e...

The issue of whether tidal forces really affect seismicity has been raised many times in the literature. Nevertheless, even though there seems to be a kind of consensus that such effects do exist, no quantitative estimates are available to relate tide parameters to changes in the level of seismic activity. Such estimation for aftershocks of large e...

This paper considers the global statistics of times of largest aftershocks relative to the times of the corresponding main shocks. A large data set was used to show that the time-dependent distribution of largest aftershocks obeys a power law distribution. This is analogous to the Omori law for the sequence of all aftershocks. It is also shown that...

The issue of whether tidal forces really affect seismicity has been raised many times in the literature. Nevertheless, even though there seems to be a kind of consensus that such effects do exist, no quantitative estimates are available to relate tide parameters to changes in the level of seismic activity. Such estimation for aftershocks of large e...

In seismology according to Båth’s well-known law, the magnitude of the strongest aftershock is on average by unity lower than the magnitude of the main shock. At the same time, most of the strongest aftershocks typically occur within a few hours after the main shock. From the practical standpoint, this activity is quite naturally perceived as a dir...

This paper shows that the number of aftershocks with a relative magnitude does not depend on the magnitude of the main shock, and, in global and regional consideration, it is characterized by an exponential distribution that is similar to the Gutenberg–Richter repeatability law. This type of distribution makes it possible to give a simple and adequ...

Probabilistic earthquake seismicity models provide just very low local expected rates of large earthquakes. In operational earthquake forecasting this makes it difficult to take preventive measures. Precursory phenomena detected in different geophysical fields may signal periods of significant rise of earthquake probabilities, but usually they may...

Seismicity of Kamchatka slab and variability of earthquake size distributions Figure 1. We use the regional catalogue of the Kamchatka seismic network. The intraplate and volcanic seismicity is removed (Levina et al., 2010). Earthquakes with M?3.5 in 1997-2017 are classified by focal depth. Earthquake size distributions in 8 zones demonstrate varia...

Characterising the state of stress in the brittle upper-crust is essential in mechanics of faulting, industrial production processes, and operational earthquake forecasting. Nevertheless, unresolved questions concern the variation of pore-fluid with depth and the absolute strength on tectonically active faults. Here we show that, along the San Andr...

We study aftershock sequences of six major earthquakes in New Zealand, including the 2016 M7.8 Kaikaoura and 2016 M7.1 North Island earthquakes. For Kaikaoura earthquake, we assess the expected number of long-delayed large aftershocks of M5+ and M5.5+ in two periods, 0.5 and 3 years after the main shocks, using 75 days of available data. We compare...

This paper deals with the rapid estimation of the hazard posed by strong aftershocks for Kamchatka and the Kuril Islands based on the 12-hour aftershocks, namely, their rate, time of expectation, and maximum magnitude. The data set consists of main shocks and aftershocks as reported in the Catalog of the Kamchatka Branch of the Geophysical Survey,...

The technique for forecasting the spatial domain where fairly intense aftershocks should be expected after a strong earthquake is considered. The paper presents the task of estimating the area prone to the strong future aftershocks using the data for the first 12 h after the main shock. The existing aftershock identification techniques are inapplic...

Lecture

Crustal faults accommodate slip either by a succession of earthquakes or continuous slip, and in most instances, both these seismic and aseismic processes coexist. Recorded seismicity and geodetic measurements are therefore two complementary data sets that together document ongoing deformation along active tectonic structures. Here we study the inf...

The method for forecasting the intensity of the aftershock processes after strong earthquakes in different magnitude intervals is considered. The method is based on the joint use of the time model of the aftershock process and the Gutenberg–Richter law. The time model serves for estimating the intensity of the aftershock flow with a magnitude large...

We describe an iterative method to combine seismicity forecasts. With this method, we produce the next generation of a starting forecast by incorporating predictive skill from one or more input forecasts. For a single iteration, we use the differential probability gain of an input forecast relative to the starting forecast. At each point in space a...

The experiment in prospective documented earthquake prediction using the algorithm Reverse Tracing of Precursors (RTP) has been started in June 2003. The algorithm is based on the analysis of a set of intermediate-term precursors in an area of a short term long-range activation of seismicity, detected by earthquake chains. Earthquake chains are clu...

We propose a multiscale method to map spatial variations in completeness magnitude Mc of earthquake catalogs. The Mc value may significantly vary in space due to the change of the seismic network density. Here we suggest a way to use only earthquake catalogs to separate small areas of higher network density (lower Mc) and larger areas of smaller ne...

Stress magnitudes and frictional faulting properties vary with depth and may strongly affect earthquake statistics. Nevertheless, if the Anderson faulting theory may be used to define the relative stress magnitudes, it remains extremely difficult to observe significant variations of earthquake properties from the top to the bottom of the seismogeni...

We propose a method to combine probabilistic and non-probabilistic earthquake forecast models into probabilistic ones. Probabilistic models estimate the expected rates of earthquake of a given magnitude on a geographic grid. Non-probabilistic models include different alarm-based models, precursors, color maps. The general procedure is to create new...

Most earthquake prediction algorithms are based on premonitory seismicity patterns. Relatively better validated by advance prediction are the intermediate-term patterns that emerge within years before a large earthquake. Accordingly, these algorithms identify periods of alarm some years in advance. Triplets of patterns providing a second approximat...

In order to examine variations in aftershock decay rate, we propose a Bayesian framework to estimate the {K,c,p}-values of the modified Omori law (MOL), λ(t) = K(c + t)-p. The Bayesian setting allows not only to produce a point estimator of these three parameters but also to assess their uncertainties and posterior dependencies with respect to the...

We propose a method to combine earthquake forecast models. The general procedure is to successively create new generations of a rate-based model by injecting into the current generation the additional knowledge carried by other input models. For a single iteration, we use the differential probability gain calculated in the Molchan diagram that eval...

We propose a conversion method from alarm-based to rate-based earthquake forecast models. A differential probability gain g(alarm)(ref) is the absolute value of the local slope of the Molchan trajectory that evaluates the performance of the alarm-based model with respect to the chosen reference model. We consider that this differential probability...

The Reverse Tracing of Precursors (RTP) algorithm for the prediction of strong earthquakes has become known owing to the successful predictions of the Tokachi-oki earthquake near Hokkaido Island and the San Simeon earthquake of California in 2003, as well as to other well-documented predictions found on the Internet, some of which also proved to be...

The statistical properties of avalanches in a dissipative particulate system under slow shear are investigated using molecular dynamics simulations. It is found that the magnitude-frequency distribution obeys the Gutenberg-Richter law only in the proximity of a critical density and that the exponent is sensitive to the minute changes in density. It...

We present an alarm-based earthquake forecast model that uses Early Aftershock STatistics (EAST model). This model is based on the hypothesis that the time delay before the onset of the power-law aftershock decay rate decreases as the level of stress and the seismogenic potential increases. Here, we estimate this time delay from , the geometric mea...

The aftershock decay rate is an important source of information on the state of stress of the brittle crust in a tectonically active region. Parametrized models of this aftershock decay rate are commonly used to compare the different regions. Here, we use the Modified Omori Law (MOL), Lambda(t)=K/(c+t)^p and a Bayesian framework to estimate the c v...

Recent studies in earthquake predictions, having time windows of several years and possibly down to several months, have led to a reformulation of the intertwined problems linking disaster preparedness with earthquake prediction. Given an earthquake prediction including a time window, magnitude, probability of false alarm, and geographic area, disa...

It was shown recently that the c-value systematically changes across different faulting styles and thus may reflect the state of stress. Hypothesizing that smaller c-values indicate places more vulnerable to moderate and large earthquakes, we suggested a simple alarm-based forecasting model, called EAST, submitted for the test in CSEP in California...

We present a method to model geomagnetic field requiring only a restricted number of measurements on magnetic survey satellite orbits. These points are chosen in an optimal -- or close to optimal -- manner relying on recent developments in the problem of numerical integration over spheres. The method allows us to compute a series of models at short...

The RTP method is a probabilistic prediction method for strong earthquakes (Keilis-Borok et al., 2004). Based on simple pattern recognition algorithms and tuned on historical seismic catalogs, RTP has been running as a prediction in advance experiment since 1997. We present a similar system aimed at improving the algorithm and tuning it to regional...

Two of the long-standing relationships of statistical seismology are power laws: the Gutenberg-Richter relation describing the earthquake frequency-magnitude distribution, and the Omori-Utsu law characterizing the temporal decay of aftershock rate following a main shock. Recently, the effect of stress on the slope (the b value) of the earthquake fr...

In the Limited Power Law model (LPL) we consider that after a triggering event - the so-called mainshock - rocks subject to sufficiently large differential stress can fail spontaneously by static fatigue. Then, earlier aftershocks occur in zones of highest stress and the c-value, i.e. the delay before the onset of the power-law aftershock decay rat...

We estimate the loading rate in southern California and the change in stress induced by a transient slip event across the San Andreas fault (SAF) system in central California, using a model of static fatigue. We analyze temporal properties of aftershocks in order to determine the time delay before the onset of the power law aftershock decay rate. I...

In a Limited Power Law model (LPL), Lambda(t) = K \frac{

In order to estimate the hazard rate distribution of the largest seismic events in Vrancea, South-Eastern Carpathians, we study temporal properties of historical and instrumental catalogues of seismicity. First, on the basis of Generalized Extreme Value theory we estimate the average return period of the largest events. Then, following Bak et al. (...

“Earthquake chains” are clusters of moderate-size earthquakes which extend over large distances and are formed by statistically rare pairs of events that are close in space and time (“neighbors”). Earthquake chains are supposed to be precursors of large earthquakes with lead times of a few months. Here we substantiate this hypothesis by mass testin...

We apply a simple linear transform, the along-track second derivative, to four years of scalar and vectorial data from the CHAMP satellite. This transform, reminiscent of techniques used in the interpretation of aeromagnetic surveys, is applied either to the geocentric spherical components of the field or to its intensity. After averaging in time a...

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...

We summarize here the results and implications of the first 2.5 years of the experiment in advance earthquake prediction by Reverse Tracing of Precursors ("RTP") approach. Prediction is based on premonitory seismicity patterns suggested by data analysis and theoretical modeling. Experiment, started in June 2003, covers so far the territories of Cal...

Aftershocks rates seem to follow a power law decay, but the question of the aftershock frequency immediately after an earthquake remains open. We estimate an average aftershock decay rate within one day in southern California by stacking in time different sequences triggered by main shocks ranging in magnitude from 2.5 to 4.5. Then we estimate the...

We describe the ongoing test of the algorithm "RTP"(Reverse Tracing of Precursors) for short-term (months in advance) prediction of strong earthquakes. Algorithm is based on integration of geodynamical models of fault networks, models of non-linear-dynamics type, and pattern recognition analysis of observed and modeled seismicity. Performance of th...

Recent work has inferred that seismicity correlates best with Earth tides in the months prior to large magnitude events (Tanaka, Fall AGU meetings, 2003, 2004). These results suggest that the crust approaches a critical state in which even small tidal stress perturbations can trigger seismicity before a large earthquake, or perhaps both the tides a...

We describe the methodology for detecting short -term earthquake precursors with characteristic lead time months. Physical mechanism underlying this methodology comprises interaction of two processes in a fault network: accumulation of energy that the earthquake will release; and triggering that release by decrease of the network's integral strengt...

Recent studies in prediction of destructive earthquakes months in advance lead to a reformulation of the interwined problems linking disaster disaster preparedness with earthquake prediction. Given a specific earthquake prediction including a time window, magnitude and geographic area, the disaster manager has to choose the optimal set of temporal...

The deviation of aftershocks number decreasing in time from the exponential low (Omori low) in the aftershocks series start can be correlated with the aftershock zone's stress state characteristics. The analysis of a large number of aftershock series generated by medium-strength earthquakes in some seismic zone allows quantitative estimation of the...

Tokachi-oki earthquake in northern Japan, September 25, 2003, magnitude 8.1, was predicted six months in advance by a short-term earthquake precursor "chain" that reflects an increase of the correlation range among small earthquakes. This prediction is part of the ongoing test of a new short-term prediction method; the test covers territories of Ja...

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 correlati...

This study explores the possibility of short-term earthquake prediction, with the lead-time months to weeks. Prediction considered is based on the evolution of seismicity preceding a strong earthquake. We have found the following two-steps sequence: 1) Within years before a strong earthquake --- rise of seismic activity, rise of earthquakes cluster...

Big perturbations of the magnetic field (amplitudes larger than 250 nT) are simply detected by subtracting the values of a model from the measurements of CHAMP satellite. Taking a full year of CHAMP data and organizing them in four subsets of three months length (spring, summer, autumn, winter), it is found that: (a) the two domains where such big...

1] In order to elucidate how structural heterogeneities affect the aftershock decay rate, we examine the aftershock sequences produced by a slider-block model of seismicity. In this model, the geometry of the seismic zone is the only free parameter and all aspects of the system are known. The power law aftershock decay rate holds only for smooth fa...

The scientific research aimed at predicting earthquakes started in the second half of nineteenth century, when seismology reached the level of a recognized scientific discipline. The desire to find tools that would permit forecasting the phenomenon under study is so natural that, as early as 1880, John Milne, a famous British engineer-seismologist...

This article explores the problem of short-term earthquake prediction based on spatio-temporal variations of seismicity. Previous approaches to this problem have used precursory seismicity patterns that precede large earthquakes with "intermediate" lead times of years. Examples include increases of earthquake correlation range and increases of seis...

1] We compare the aftershock decay rate in natural data with predictions from a stochastic analytical model based on a Markov process with stationary transition rates. These transition rates vary according to the magnitude of a scalar representing the state of stress and defined as the overload. Thus, the aftershock decay rate in the model is a sum...

Our point of departure is provided by premonitory seismicity patterns found in models and observations. They reflect increase of earthquake correlation range and seismic activity within "intermediate" lead-time of years before a strong earthquake. A combination of these patterns, in renormalized definition, precedes within months eight out of nine...

Reliable detection of long-range earthquake correlations is an emerging problem important for understanding of the dynamics of the lithosphere. Recently, its importance became even more alarming since there is growing evidence that increase of earthquake correlation length (ECL) is associated with approach of a large earthquake. We outline several...

Some elements of the model of scaling organization of fracture tectonics (SOFT) are incorporated into the model of block structure dynamics (BSD). The resulting new model permits to obtain a power law relationship between earthquake energy and fault area with an exponent 3/2, as for observed seismicity. This is an important advantage of the new mod...

SummaryA time-dependent stochastic process with three states (solid, broken and moving) is considered in a hierarchical system made of embedded cells of increasing levels. An earthquake of a given scale k is associated with the moving state of a cell of level k and results from the coherent self-organization of fractures of lower scales. A direct c...

We represent temporal decay of aftershocks as a sum of independent exponential de- cays with different characteristic "times of life" . This can be interpreted in terms of a Markov process with a stationary transition probability = 1/ (Scholz, 1968). The rate depends on the local overload s (stress minus strength). In the frames of this model the p...

The vulnerability of the world civilization to disastrous earthquakes keeps increasing rapidly. Therefore, earthquake prediction is widely recognized as one of the global challenging problems facing the mankind in the 21st century. The recent scientific ad- vances in understanding the hierarchical nature of the lithosphere and its dynamics did resu...

The lithosphere of the Earth is structured as a hierarchical system of volumes of different sizes, from about 10 tectonic plates to about 1025 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, c...

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