Why Does Theoretical Physics Fail to Explain and Predict Earthquake Occurrence?

Kagan, Yan Y.

doi:10.1007/3-540-35375-5_12

Cited by 27 publications

(23 citation statements)

References 140 publications

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“…Many researchers interpret the c value as having a physical significance; they should then be able to explain why c estimates are so unstable. This is in contrast to other seismicity parameters, such as the p value of Omori's law or the b value of the Gutenberg-Richter relation, which hardly (if at all) change (KAGAN, 2006).…”

Section: Comparison Of Models and Results With Etascontrasting

confidence: 57%

Earthquake Patterns in Diverse Tectonic Zones of the Globe

Kagan

Bird

Jackson

2010

Pure Appl. Geophys.

108

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Abstract-We extend existing branching models for earthquake occurrences by incorporating potentially important estimates of tectonic deformation and by allowing the parameters in the models to vary across different tectonic regimes. We partition the Earth's surface into five regimes: trenches (including subduction zones and oceanic convergent boundaries and earthquakes in outer rise or overriding plate); fast spreading ridges and oceanic transforms; slow spreading ridges and transforms; active continental zones, and plate interiors (everything not included in the previous categories). Our purpose is to specialize the models to give them the greatest possible predictive power for use in earthquake forecasts. We expected the parameters of the branching models to be significantly different in the various tectonic regimes, because earlier studies (BIRD and KAGAN in Bull Seismol Soc Am 94(6): [2380][2381][2382][2383][2384][2385][2386][2387][2388][2389][2390][2391][2392][2393][2394][2395][2396][2397][2398][2399] 2004) found that the magnitude limits and other parameters differed between similar categories. We compiled subsets of the CMT and PDE earthquake catalogs corresponding to each tectonic regime, and optimized the parameters for each, and for the whole Earth, using a maximum likelihood procedure. We also analyzed branching models for California and Nevada using regional catalogs. Our estimates of parameters that can be compared to those of other models were consistent with published results. Examples include the proportion of triggered earthquakes and the exponent describing the temporal decay of triggered earthquakes. We also estimated epicentral location uncertainty and rupture zone size and our results are consistent with independent estimates. Contrary to our expectation, we found no dramatic differences in the branching parameters for the various tectonic regimes. We did find some modest differences between regimes that were robust under changes in earthquake catalog and lower magnitude threshold. Subduction zones have the highest earthquake rates, the largest upper magnitude limit, and the highest proportion of triggered events. Fast spreading ridges have the smallest upper magnitude limit and the lowest proportion of triggered events. The statistical significance of these variations cannot be assessed until methods are developed for estimating confidence limits reliably. Some results apparently depend on arbitrary decisions adopted in the analysis. For example, the proportion of triggered events decreases as the lower magnitude limit is increased, possibly because our procedure for assigning independence probability favors larger earthquakes. In some tests we censored earthquakes occurring near and just after a previous event, to account for the fact that most such earthquakes will be missing from the catalog. Fortunately the branching model parameters were hardly affected, suggesting that the inability to measure immediate aftershocks does not cause a serious estimation bias. We compare our branching m...

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Section: Comparison Of Models and Results With Etascontrasting

confidence: 57%

Earthquake Patterns in Diverse Tectonic Zones of the Globe

Kagan

Bird

Jackson

2010

Pure Appl. Geophys.

108

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“…the cumulative moment versus time curve. Such cumulative curves have also been reported for theoretical models such as for the Critical Continuum-State Branching Model of Earthquake Rupture [50]. Precursory accelerating moment release before large earthquakes has been a widely discussed phenomenon until recent years, being regarded as observational evidence for the controversial critical-point-like model of earthquake generation [51,52].…”

Section: The Temporal Distribution Of Aftershock Magnitudesmentioning

confidence: 60%

A fractal model of earthquake occurrence: Theory, simulations and comparisons with the aftershock data

Bhattacharya

Chakrabarti

Kamal

2011

J. Phys.: Conf. Ser.

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Abstract. Our understanding of earthquakes is based on the theory of plate tectonics. Earthquake dynamics is the study of the interactions of plates (solid disjoint parts of the lithosphere) which produce seismic activity. Over the last about fifty years many models have come up which try to simulate seismic activity by mimicking plate plate interactions. The validity of a given model is subject to the compliance of the synthetic seismic activity it produces to the well known empirical laws which describe the statistical features of observed seismic activity. Here we present a review of one such, purely geometric, model of earthquake dynamics, namely The Two Fractal Overlap Model. The model tries to emulate the stick-slip dynamics of lithospheric plates with fractal surfaces by evaluating the time-evolution of overlap lengths of two identical Cantor sets sliding over each other. As we show later in the text, some statistical aspects of natural seismicity are naturally captured by this simple model. More importantly, however, this model also reveals a new statistical feature of aftershock sequences which we have verified to be present in nature as well. We show that, both in the model as well as in nature, the cumulative integral of aftershock magnitudes over time is a remarkable straight line with a characteristic slope. This slope is closely related to the fractal geometry of the fault surface that produces most of thee aftershocks. We also go on to discuss the implications that this feature may have in possible predictions of aftershock magnitudes or times of occurrence. IntroductionMany models of natural seismicity have been proposed over the last half-decade and more. These cover a very broad range of approaches ranging from purely physical to purely statistical. The relative successes of these very diverse models is testament to the great complexity involved in the production of natural seismicity and points to the fact that the correct model is probably neither extreme and is some elusive combination of these approaches. However, an approach that has been less pursued to some extent is the investigation of the role of the fractal surface geometry of a fracture surface topography (or self affine for most natural surfaces) in producing the known statistical properties of natural seismicity. The model we propose in this article incorporates this fractal topography of the fracture surface in a simplistic way.

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“…[1][2][3][4] The correlations that may arise between in the dynamics earthquakes occurrence have been the subject of many studies conducted around the world, especially in the most affected countries. [5][6][7][8][9][10][11] Recently, worldwide the research activity concerning the seismic phenomenon has focused on the study of correlations viewed in the time series space diagram. [1][2][3][4] The study of seismic activity has been developed for smaller scales; however, the challenge is to find the seismic activity for larger scales of Richter considering the smaller results.…”

Section: Introductionmentioning

confidence: 99%

“…So that, the scaling laws of temporal and spatial variability of earthquakes have been obtained, considering several seismic regions with different tectonic properties. [5][6][7][8] However, despite of the best efforts developed around the world to know the seismic activity, specialists in the area are still working to understand its dynamics. [5][6][7][8][9][10][11] A worldwide challenge is the prediction of earthquakes, specifically for large earthquakes.…”

Section: Introductionmentioning

confidence: 99%

Seismic Activity Seen Through Evolution of the Hurst Exponent Model in 3d

et al. 2016

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The dynamics seismic activity occurred in the Cocos Plate-Mexico is analyzed through the evolution of Hurst exponent and 3D fractal dimension, under the mathematical fractal structure based on seismic activity time series, taking into account the magnitude (M ) as the main parameter to be estimated. The seismic activity time series and, annual intervals are considered first for finding the Hurst exponent of each year since 1988 (the year in which the database is consistent) until 2012, and then the following years are accumulated describing the cumulative Hurst exponent. The seismic activity description is based on Cocos Plate data information; during a period conform from 1 January 1988 to 31 December 2012. Analyses were performed following methods, mainly considering that the Hurst exponent analysis provides the ability to find the seismicity behavior time-space, described by parameters obtained under the fractal dimension and complex systems.

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Why Does Theoretical Physics Fail to Explain and Predict Earthquake Occurrence?

Cited by 27 publications

References 140 publications

Earthquake Patterns in Diverse Tectonic Zones of the Globe

Earthquake Patterns in Diverse Tectonic Zones of the Globe

A fractal model of earthquake occurrence: Theory, simulations and comparisons with the aftershock data

Seismic Activity Seen Through Evolution of the Hurst Exponent Model in 3d

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