The Formation of Oscillation Patterns Based on the Planetary Gravitational Field and Their Suitability for Earthquake Prediction

The fluctuating planetary gravitational field influences not only activities on the Sun but also on the Earth. A special correlation function describes the harmonics of these fluctuations. Groups of earthquakes form oscillation patterns that differ significantly from randomly chosen control groups. These patterns are suitable as an element of an AI for the probability of earthquakes.

Earthquake prediction from China's mobile gravity data

The relation between plate tectonics and earthquake evolution is analyzed systematically on the basis of 1998-2010 absolute and relative gravity data from the Crustal Movement Observation Network of China. Most earthquakes originated in the plate boundary or within the fault zone. Tectonic deformation was most intense and exhibited discontinuity within the tectonically active fault zone because of the differential movement; the stress accumulation produced an abrupt gravity change, which was further enhanced by the earthquake. The gravity data from China's Mainland since 2000 obviously reflected five major earthquakes （Ms 〉 7）, all of which were better reflected than before 2000. Regional gravity anomalies and a gravity gradient change were observed in the area around the epicenter about 2 or 3 years before the earthquake occurred, suggesting that gravity change may be a seismic precursor. Furthermore, in this study, the medium-term predictions of the Ms7.3 Yutian, Ms8.0 Wenchuan, and Ms7.0 Lushan earthquakes are analytically pre- sented and evaluated, especially to estimate location of earthquake.

V_p/V_s Anisotropy and Implications for Crustal Composition Identification and Earthquake Prediction

The ratio of P- to S-wave velocities （Vp/Vs） is regarded as one of the most diagnostic properties of natural rocks. It has been used as a discriminant of composition for the continental crust and provides valuable constraints on its formation and evolution processes. Furthermore, the spatial and temporal changes in Vp/Vs before and after earthquakes are probably the most promising avenue to understanding the source mechanics and possibly predicting earthquakes. Here we calibrate the variations in Vp/Vs in dry, anisotropic crustal rocks and provide a set of basic information for the interpretation of future seismic data from the Wenchuan earthquake Fault zone Scientific Drilling （WFSD） project and other surveys. Vp/Vs is a constant （Ф0） for an isotropic rock. However, most of crustal rocks are anisotropic due to lattice-preferred orientations of anisotropic minerals （e.g., mica, amphibole, plagioclase and pyroxene） and cracks as well as thin compositional layering. The Vp/Vs ratio of an anisotropic rock measured along a selected pair of propagation-vibration directions is an apparent value （Фy） that is significantly different from the value for its isotropic counterpart （Ф0）. The usefulness of apparent Vp/Vs ratios as a diagnostic of crustal composition depends largely on rock seismic anisotropy. A 5% of P- and S-wave velocity anisotropy is sufficient to make it impossible to determine the crustal composition using the conventional criteria （Vp/Vs≤1.756 for felsic rocks, 1.756〈Vp/Vs≤1.809 for intermediate rocks, 1.809〈Vp/Vs≤1.944 for mafic rocks, and Vp/V2〉1.944 fluidfilled porous/fractured or partially molten rocks） if the information about the wave propagation-polarization directions with respect to the tectonic framework is unknown. However, the variations in Vp/Vs measured from borehole seismic experiments can be readily interpreted according to the orientations of the ray path and the polarization of the shear waves with respect to the present-day principal stress directions （i.e., the orientation of cracks） and the frozen fabric （i.e., foliation and lineation）.

Studies and experiments on earthquake prediction during 1999～2002

This paper briefly reviewed the research progresses of earthquake prediction and/or forecasting in China during 1999~2002, especially focused on mid-short term prediction methods with approaches of seismicity, crustal deformation, electromagnetism, ground water and the analysis by synthesis, and the application of the methods to the practice of earthquake prediction.

An scientific evaluation of annual earthquake prediction ability

The scientific idea of earthquake prediction in China is introduced in this paper. The various problems on evaluation of earthquake prediction ability are analyzed. The practical effect of prediction on annual seismic risk areas in 1990~2000 in China is discussed based on R-value evaluation method, and the ability of present earthquake prediction in China is reviewed.

On numerical earthquake prediction

Can earthquakes be predicted？ How should people overcome the difficulties encountered in the study of earthquake prediction？ This issue can take inspiration from the experiences of weather forecast. Although weather forecasting took a period of about half a century to advance from empirical to numerical forecast, it has achieved significant success. A consensus has been reached among the Chinese seismological community that earth- quake prediction must also develop from empirical fore- casting to physical prediction. However, it is seldom mentioned that physical prediction is characterized by quantitatively numerical predictions based on physical laws. This article discusses five key components for numerical earthquake prediction and their current status. We conclude that numerical earthquake prediction should now be put on the planning agenda and its roadmap designed, seismic stations should be deployed and observations made according to the needs of numerical prediction, and theoretical research should be carried out.

Light for Earthquake Prediction:Shocks before the L'Aquila Earthquake of April 6,2009

The temporal-spatial distribution of mid-small earthquakes in Italy and its surroundings from January 1 to April 5,2009 shows that there were significant foreshocks before the moderate L'Aquila earthquake of April 6,2009.The enhancement of frequency and intensity of small earthquakes and their concentrating tendency to the future main shock have provided a comprehensive case for digging methods of earthquake forecasting with foreshocks.

New Progress in the Application of Satellite Thermal Infrared Imagery to Earthquake Prediction

The concept of stochastic resonance (SR) has been introduced into the analysis of satellite thermal infrared images. Six kinds of anomalous phenomena related to crustal movement were recognized in satellite thermal infrared images. Six diagnostic indicators for the prediction of global earthquakes with magnitude ≥6.0 and their quantitative evaluation standards have been established. The microscopic behavior of global crustal movement is successfully controlled by using satellite thermal infrared imagery, and the occurrence time and magnitude of over 80% of global strong earthquakes occurred since the foundation of the observation station have been successfully predicted. It is believed that the combination of satellite thermal infrared information with macroscopic anomalous phenomena will play an important role in earthquake hazard reduction.

Application of support vector machine to synthetic earthquake prediction

This paper introduces the method of support vector machine （SVM） into the field of synthetic earthquake prediction, which is a non-linear and complex seismogenic system. As an example, we apply this method to predict the largest annual magnitude for the North China area （30°E-42°E, 108°N-125°N） and the capital region （38°E-41.5°E, 114°N-120°N） on the basis of seismicity parameters and observed precursory data. The corresponding prediction rates for the North China area and the capital region are 64.1% and 75%, respectively, which shows that the method is feasible.

New indexes and methods in earthquake prediction research

This paper gives a brief introduction to a few new indexes and methods published in recent issues of seismological literature which have been explored especially by the authors and many of their collaborators for applying in earthquake prediction research. The new indexes include the statistical indexes of seismicity (Morishita index Iδ, the parameters C and b-value spectrum derived from the magnitude-frequency relation, etc. )and indexes describing the dynamical characteristics of seismic waves obtained from digitized seismologicrecords (wave form linearities, spectral characteristics, etc. ). The new methods fall into two categories:namely the methods of non-linear sciences (fractal analysis, self-similarity and self-organization structure,neural network) and graphical analysis methods of multi-dimensional data (face analysis, projection pursuit,chronogeometric analysis ).

Calculation of b value and its application in earthquake prediction

The improved calculation method of b value is presented in tills paper. The method can enlarge the role of earthquake occurrence frequency in b value calculation and thus increase the b value variation amplitude. In this case,the combination structure variation between earthquake magnitudes and corresponding frequencies could be shown clearly. According to the calculation and analysis for limited mainshocks in the complete seismicity data of selected monitored area with assigned consistent lowest magnitude, the precursor anomaly features, quantitative indexes and the calculation formula of relative subject function of b value variation have been preliminarily worked out. The prediction in short period (from 1 to 3 months) for damage earthquakes in the monitored area mentioned above can be put forward on the basis of the results of quantitative calculation and analysis.

Seismicity anomalies before the great earthquake of M_S=8.1 in the Kunlun Pass and its significance to earthquake prediction

A great earthquake of MS=8.1 took place in the west of Kunlun Pass on November 14, 2001. The epicenter is lo-cated at 36.2N and 90.9E. The analysis shows that some main precursory seismic patterns appear before the great earthquake, e.g., seismic gap, seismic band, increased activity, seismicity quiet and swarm activity. The evolution of the seismic patterns before the earthquake of MS=8.1 exhibits a course very similar to that found for earthquake cases with MS7. The difference is that anomalous seismicity before the earthquake of MS=8.1 involves in the lar-ger area coverage and higher seismic magnitude. This provides an evidence for recognizing precursor and fore-casting of very large earthquake. Finally, we review the rough prediction of the great earthquake and discuss some problems related to the prediction of great earthquakes.

A finite-element simulation of 2008 Wenchuan earthquake and implications for numerical earthquake prediction

The dynamic process of the 2008 Wenehuan earthquake is simulated by finite-element method （ FEM）, and the results suggest that we may be able to estimate the occurrence time, location, and magnitude of similar earthquakes in the future. Thus a numerical earthquake prediction （NEP） program is proposed; the reliability of it is dependent on its gradual refinement and the parameters used in the models.

Reducing of Seismic Vulnerability ＆ Short-Time Earthquake Prediction： Methods and Instruments of Nonlinear Seismology

Elimination of human losses is the main and immediate task in the seismic vulnerability problem.The authors suggest the ways of development of seismic research and discussion of defense problems for reducing of seismic vulnerability. It is the ways of nonlinear seismology region. Unconditionally seism zoning and the theory of catastrophes allow reduce human losses and building destruction. But well-known isoseists are the private case of caustic catastrophe theory or seismo-acoustics, so seism zoning can be amounted to 6 elementary catastrophe forms. It will better help to predict seismic actions. The short-time local prediction of seismic events is general method for strong reducing of human losses. This method takes into account chaotic properties of stress fields and waves and the peculiarities of urban area. It bases on the natural seismo-emission phenomenon and is realized by long-time monitoring, which gives statistically and geographically continuous picture （chart） of seismic noise level inside geologic media. The instruments of this strategy are shock and pressure-proofed seismometers for long-time monitoring and control the state of geological media including underwater shelf areas. The authors think that the active protecting for cities and buildings as the best modem form of people safety consists in stress discharge of geologic media. Ultrasonic wave defense includes and bases on strong interaction between powerful waves from earthquake and ultrasonic wave train. The authors want to point out that the technical objects may be used lbr the investigation of earthquakes induced and some reasons of seismic vulnerability. Also reducing of seismic vulnerability contains as component kinetic acting on volcano at the pre-explosive stage. The interesting and important aspect of defense problem is observation of the inharmonic wave processes in the soil and quasi-constant forces as the nearest seismic analogue of radiation forces in nonlinear acoustics under powerful earthquake seismic tremor.

Short-term Earthquake Prediction in the Sichuan-Yunnan Region Using the Method of Modulated Earthquakes

By scanning modulated or un-modulated earthquakes spatio-temporally in the region of Sichuan-Yunnan,short-term non-stationary seismic precursory patterns were extracted with significant difference and the characteristic of non-stationary short-term seismic anomalies were analyzed as well as prediction efficiency of modulated small earthquakes before a strong earthquake. Besides,small earthquake modulation ratios near the region of the epicenter were calculated and sorted by time. The results indicated that there were significant effects using the modulated earthquake method to predict earthquakes greater than MS6. 0 in a short time. Before the MS8. 0 Wenchuan earthquake,there were obvious short-term precursory seismicity gap patterns of modulated small earthquakes.

A Retrospective Analysis about the Italy Emilia M6.0 Earthquake Prediction

Cloud anomaly is a new kind of earthquake precursor that is still in the great controversy. Here we report an example of earthquake prediction based on cloud satellite anomaly. According to the cloud anomaly that appeared over eastern Italy on 21-23 April 2012, we made a prediction to Italy National Institute of Geophysics and Volcanology (INGV) that there will be a M5.5 - M6.0 earthquake in Italy in 30 days. Finally, the M6.0 quake occurred in northern Italy on 20 May 2012 and this verified our prediction. In this paper we extend the cloud image data from 2010 to 2013 and found 23 cloud anomalies totally, among them only the duration of the cloud on April 21-23 2012 exceed the 2 times, even 3 times of standard deviation threshold and it can be considered as a significant anomaly. Our analysis shows that the quake’s date and magnitude can be estimated accurately with the formula, and the epicenter can be estimated with the temperature anomaly method with 100 - 200 km error. This paper shows a promising method in earthquake prediction, of course it is only one example, and it still needs more examples to verify this method.

Earthquake Prediction Research in China

China is the country with the most earthquakes and the most serious hazards from continental earthquakes in the world. During the 1960s and 1970s, a series of strong earthquakes attacked the cities and counties in China causing great damage and many casualties. The most striking one was the Tangshan earthquake ( M S7 8) in July 1976, in which over 240,000 people died and a large industrial city was leveled. Public demand for earthquake forecasting surged after this disaster. From the mid-1960s, systemic research on earthquake forecasting has evolved throughout the country. In this paper the main advances in earthquake prediction research in China have been summarized.

The idea and project of the “Medium－Scale Experiment Field for Earthquake Prediction”──Research on observations and applications of mining earthquake in Mentougou Coal Mine

A brief account of the development of the research on mining earthquakes and the general situation of the Mentougou Coal Mine medium scale experiment field for earthquake prediction and the project of monitor and prediction is given. The differences of waveforms between mining earthquakes and natural earthquakes is discussed. The magnitude frequency distribution of the 79 000 mining earthquakes of over M L1.0 from 1984 to 1995 is summarized . Finally, taking PH and PV, the principal compressive stress components of the focal mechanism of the mining earthquakes, as the criteria, analyses the stress background of the 12 large mining earthquakes.

Measurement of Anomalous Radon Gas Emanation Across the Yammouneh Fault in Southern Lebanon: A Possible Approach to Earthquake Prediction

The eastern Mediterranean region is an active tectonic setting that includes the Dead Sea Transform Fault, which forms the boundary between the African and the Arabian Plates and crosses Lebanon from south to north, striking in a restraining bend around 25–30°NE. The major structural feature in Lebanon is the Yammouneh Fault, which reaches to Syria and southern Turkey in a north–south direction. Measurements of radon gas concentration and exhalation rates in two locations along the southern segment of the Yammouneh Fault in south Lebanon were performed. Two profiles in the El-Khiam basin and Blat pull-apart basin and perpendicular to the Yammouneh Fault trace were analyzed. An approximate fault width 25–30 m wide was determined in the El-Khiam study area. Temporal increase of radon concentration was measured and correlated with stress/strain tectonic activity and stress drops along the studied fault segment boundary.Anomalous variable radon concentrations were detected during one of the measurements where an earthquake occurred in the region of Tiberias Lake in northern Palestine along the Yammouneh Fault in the study area. Measurements of radon concentration along a station’s profile in Blat village did not show any radon anomalous variation due to the discontinuity along the fault(pull-apart), and possible absence of stress and energy accumulation along the Yammouneh Fault line in that location.

Application of the value of nonlinear parameters H and ΔH in strong earthquake prediction

In this paper, the relation that the curves of nonlinear parameter H and its difference Δ H bear with strong earthquakes in North China has been studied. First, the RSH algorithm has been applied to the North China region; the schemes of six quantitative prediction indexes have been studied in detail and then tested by tracing back predictions. The result shows that all the six prediction schemes are of certain prediction efficiency and have passed the test. Among the six schemes, A and E are of the best effect, with correlation coefficients R of 0.47 and 0.48 respectively. We recommend these two schemes for practical use in prediction in the future. Furthermore, the relation between the curve of Δ H (the difference of H) and strong earthquake has been studied. Based on the above results, the RSΔH algorithm that uses the Δ H value to predict strong earthquake has been put forward and applied to predict strong earthquakes in North China. The correlation coefficient R of tracing back prediction by this method is 0.45; this means that this method is also of better prediction efficiency. A combined application of these two algorithms has also been proposed. By the combined method, the time length spanned by false predictions can be shortened and thus the R value can be raised.