An Attempt to Analyze a Human Nervous System Algorithm for Sensing Earthquake Precursors

We statistically validate the 2011-2022 earthquake prediction records of Ada, the sixth finalist of the 2nd China AETA in 2021, who made 147 earthquake predictions (including 60% of magnitude 5.5 earthquakes) with a prediction accuracy higher than 70% and a confidence level of 95% over a 12-year period. Since the reliable earthquake precursor signals described by Ada and the characteristics of Alfvén waves match quite well, this paper proposes a hypothesis on how earthquakes are triggered based on the Alfvén (Q G) torsional wave model of Gillette et al. When the plume of the upper mantle column intrudes into the magma and lithosphere of the soft flow layer during the exchange of hot and cold molten material masses deep inside the Earth’s interior during ascent and descent, it is possible to form body and surface plasma sheets under certain conditions to form Alfven nonlinear isolated waves, and Alfven waves often perturb the geomagnetic field, releasing huge heat and kinetic energy thus triggering earthquakes. To explain the complex phenomenon of how Ada senses Alvfen waves and how to locate epicenters, we venture to speculate that special magnetosensory cells in a few human bodies can sense earthquake precursors and attempt to hypothesize an algorithm that analyzes how the human biological nervous system encodes and decodes earthquake precursors and explains how human magnetosensory cells can solve complex problems such as predicting earthquake magnitude and locating epicenters.

Research on Earthquake Precursor Attractor and Its Predictability

Based on the body strain observation data at Liyang and Xuzhou stations, the Correlation Dimension D2 and the second-order Renyi entropy K2 of the attractor are calculated and studied. In addition, a new method of evaluating the longest predictable time of precursor attractor is advanced under the condition of a certain anomalous criterion rule. The conclusion indicates that the body strain precursor attractor is one of the chaotic attractors and it has some determinate change rules such as the dimension declines before an earthquake and the number of the independent factors on which the variation of the system depends is within the range of 5 - 12. The conclusion also indicates that the longest evaluated predictable time of the body strain attractor is 213 days at the Liyang station and 342 days at the Xuzhou station. It is clear that this research can be of great reference value for recognizing the nonlinear behavior of precursor attractors and for evaluating the predictability of different

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.

Satellite Thermal Infrared Earthquake Precursor to the Wenchuan M_s 8.0 Earthquake in Sichuan,China,and its Analysis on Geo-dynamics

Based on an interpretation and study of the satellite remote-sensing images of FY-2C thermal infrared 1st wave band （10.3-11.3 μm） designed in China, the authors found that there existed obvious and isolated satellite thermal infrared anomalies before the 5.12 Wenchuan Ms 8.0 Earthquake. These anomalies had the following characteristics： （1） The precursor appeared rather early： on March 18, 2008, i.e., 55 days before the earthquake, thermal infrared anomalies began to occur; （2） The anomalies experienced quite many and complex evolutionary stages： the satellite thermal infrared anomalies might be divided into five stages, whose manifestations were somewhat different from each other. The existence of so many anomaly stages was probably observed for the first time in numerous cases of satellite thermal infrared research on earthquakes; （3） Each stage lasted quite a long time, with the longest one spanning 13 days; （4） An evident geothermal anomaly gradient was distributed along the Longmen seismic fracture zone, and such a phenomenon might also be discovered for the first time in satellite thermal infrared earthquake research. This discovery is therefore of great guiding and instructive significance in the study of the earthquake occurrence itself and the trend of the postearthquake phenomena.

Anomaly detection of earthquake precursor data using long short-term memory networks

Earthquake precursor data have been used as an important basis for earthquake prediction.In this study,a recurrent neural network(RNN)architecture with long short-term memory(LSTM)units is utilized to develop a predictive model for normal data.Furthermore,the prediction errors from the predictive models are used to indicate normal or abnormal behavior.An additional advantage of using the LSTM networks is that the earthquake precursor data can be directly fed into the network without any elaborate preprocessing as required by other approaches.Furthermore,no prior information on abnormal data is needed by these networks as they are trained only using normal data.Experiments using three groups of real data were conducted to compare the anomaly detection results of the proposed method with those of manual recognition.The comparison results indicated that the proposed LSTM network achieves promising results and is viable for detecting anomalies in earthquake precursor data.

On Application of Big Data Mining in Earthquake Precursor Observation

Research and application of big data mining,at present,is a hot issue. This paper briefly introduces the basic ideas of big data research, analyses the necessity of big data application in earthquake precursor observation,and probes certain issues and solutions when applying this technology to work in the seismic-related domain. By doing so,we hope it can promote the innovative use of big data in earthquake precursor observation data analysis.

Comprehensive Approaches to Earthquake Prediction

There may be various anomalies from fields of multi-discipline before large earthquakes, including seismological anomalies and the anomalous changes in crustal deformation, underground fluids, geochemistry, geomagnetic fields, ground resistivity, etc. Precursors of a single discipline only reflect the process of earthquake preparation from one aspect. Only when various precursors from multi-disciplined fields are put into a unified process of earthquake preparation can the process be understood and identified comprehensively. The comprehensive methods used in earthquake prediction are outlined in this paper. The relationship that the forthcoming main shock bears with the precursory features such as the time-space distribution, the order of the precursors, etc. is analyzed. Research shows that a few of the main shocks can be predicted with the comprehensive methods to some extent.

地震学英文科技期刊国际影响力提升实践--以Earthquake Research Advances期刊为例

提升我国地震学英文科技期刊的国际影响力,对于增强我国地震学在国际学术领域的话语权具有重要意义,同时也能吸引更多国外优秀科研论文在我国期刊上发表。本文以中国地震局主管、中国地震台网中心主办的《地震研究进展(英文)》(Earthquake Research Advances)为例,详细探讨了提升英文科技期刊国际影响力的方法,旨在为推动我国地震学英文期刊的高质量发展提供参考。

The medium- and short-term prediction methods of strong earthquakes based on neural network

The field of neural network has found solid application in the past ten years and the field itself is still developing rapidly. Neural network is composed of many simple elements operating in parallel. A neural network can be trained to perform a particular mapping and this is the basis of its application to practical problems. In this paper, new methods for predicting the strong earthquakes are presented based on neural network. Neural network learns from existing earthquake sequences or earthquake precursors how to make medium and short term prediction of strong earthquakes. This paper describes two neural network prediction models. One is the model based on earthquake evolution sequences, which is applied to the modeling of the magnitude evolution sequences in the Mainland of China, the other is based on earthquake precursors, which is applied to the modeling of the occurrence time of strong earthquakes in North China. Test results show that the prediction methods based on neural networks are efficient, and convenient. They would find more application in the future.

An approach on dynamic earthquake prediction by georesistivitymeasurements

Experiences on earthquake prediction accumulated by the Chinese scientists in the last 20 years were synthetically analyzed. A prediction program was set up to demonstrate the development of the georesistivity anomaly by using of the dynamic image, accordingly the earthquake prone area can be recognized. By revising the DYBS Ⅰ, which was developed in 1989, and adding some latest achievements, we worked out a software on earthquake prediction by the geoelectric method the DYBS Ⅱ. Some new feature of DYBS Ⅱ are: the anomalous area may be determined by the space distribution and its time variation of geoelectric parameters; The dynamic process that is associated with the development of earthquake anomaly can be displayed on the computer screen; Technique for the prediction of an impending earthquake was included too. Some results of the Tangshan earthquake were presented at the end of this paper.

Advantages of GNSS in Monitoring Crustal Deformation for Detection of Precursors to Strong Earthquakes

Earthquake predictions inChinahave had rare successes but suffered more tragic setbacks since the Xintai earthquake in 1966. They have developed with twists and turns under the influence of the viewpoint that earthquakes are unpredictable etc. Though the Wenchuan earthquake of M8.0 in2008 inChina and the 2011 Tohoku earthquake of M9.0 inJapan were failed to predict, the GPS observations before and after these 2 events have shown that there were precursors to these events and large earthquakes are predictable. Features of different observation techniques, data processing methods are compared and some recent studies on precursory crustal deformations are summarized, so various advantages of GPS technique in monitoring crustal deformation are emphasized. The facts show that anomalies or precursors detected from GPS observations before the great Wenchuan earthquake have been the most remarkable results of explorations on crustal movements and earthquake precursors in China. GPS is in deed an excellent observation technique for earthquake prediction.

The earthquake precursor detected in a granular medium and a proposed model for the propagation of precursive stress-strain signal

A way to detect the seismic precursor in granular medium is described and a model of propagation for precursive stress-strain signals is proposed.A strain sensor buried in a sandpit is used to measure a seismic precursor signal.The signal has been investigated and confirmed to originate from a specific earthquake.A comparison of simulated and experimental signals indicates that the signal results from the strain in the earth's strata.Based on the behavioral characteristics of granular materials,an analysis of why this method can be so sensitive to the seismic strain signal is undertaken and a model for the propagation of this stress-strain signal is proposed.The Earth's lithosphere is formed of tectonic plates,faults and fault gouges at their boundaries.In the case of the quasi-static mechanics of seismic precursory stress-strain propagation,the crustal lithosphere should be treated as a large-scale granular system.During a seismogenic event,accumulated force generates the stick-slip motion of adjacent tectonic plates and incrementally pushes blocks farther apart through stick-slip shift.The shear force released through this plate displacement causes soil compression deformation.The discrete properties of the sand in the sandpit lead to the sensitive response of the sensor to the deformation signal which enables it to detect the seismic precursor.From the analysis of the mechanism of the stress-strain propagation in the lithosphere,an explanation is found for the lack of signal detection by sensors installed in rocks.The principles and method presented in this paper provide a new technique for investigating seismic precursors to shallow-source earthquakes.

Intermediate-Term Seismic Precursors to the Loma Prieta California Earthquake of 1989

We use precise locations of earthquakes to study forerunning seismic activity to the 1989 Loma Prieta earthquake of magnitude 6.9 to the south of San Francisco, California, USA. Relocated shocks of magnitude 4.3 to 5.4 and smaller micro-earthquakes define a distinct zone of nearly the same orientation as the mainshock. That separate zone broke in the 15 months prior to the 1989 mainshock. That feature, which we call the Lake Elsman fault zone, is identified as the site of a prominent intermediate-term (yearly) precursor very close to the coming 1989 mainshock. That zone experienced a relatively large stress decrease during the nearby great earthquake of 1906. From the occurrence of the Lake Elsman shocks, we deduce that stress drop was only restored in the 15 months prior to the 1989 main event. Those stresses are consistent with little forerunning seismic activity in the region after 1906, later increases just before the 1989 mainshock and a decrease in activity thereafter. The southern Santa Cruz mountains segment of the San Andreas Fault zone, the location of the 1989 mainshock, had not been the site of events of magnitude 5 and larger for many decades prior to the occurrence of Lake Elsman earthquakes of magnitude 5.3 and 5.4 in 1988 and 1989. High-preci- sion locations readily available in real-time might be used to monitor similar possible precursory activity very close to the San Andreas and other transform faults.

Review of the Research of the 2011 Mw9.0 Tohoku-Oki Earthquake

On March 11,2011, a M_W9.0 earthquake occurred in the Japan Trench, causing tremendous casualties,and attracting extensive concern. Based on the results of related research,this paper analyzes the observations,phenomena and understandings of the earthquake from varied aspects,and obtains four main conclusions.(1) The earthquake,occurring in the subduction zone in the Japan Trench located in the northwest boundary of the pacific plate has two zones of concentrated coseismic slip at different depths,and the slip in the deep zone is relatively small. Though there have been many M7. 0 historical earthquakes,slips in the shallow zone are large,but there have been few historical strong earthquakes.(2) Constrained by GPS data,the study of fault movement shows that fault movement in the Japan Trench has a background of widely distributed stability and locking( the locking zone is equivalent that of coseismic rupture zone). Perturbation occurred after the 2008 M8. 0 Hokkaido earthquake,several M7. 0 events had after slips larger than the coseismic slip,and two obvious slow slip events were recorded in 2008 and2011. Eventually,the March 9,2011 M7. 0 foreshock and the March 11,2011 M_W9.0 mainshock occurred. The pre-earthquake changing of the fault movement in the Japan Trench is quite clear.(3) Traditional precursory observation show no obvious anomaly,possibly due to monitoring reason. Anomaly before earthquake consists of high stress state in focal zone reflected by some seismic activity parameters,short period anomaly in regional ground motion,etc.(4) The analysis of physical property in focal zone aroused more scientific issues,for example,is there obvious difference between physical property in focal zone and its vicinity? Does frictional property of fault determine seismogenic ability and rupture process? Whether pre-earthquake fault movement include pre-slips? Could deep fluid affect fault movement in focal zone? Experience is the best teacher,and authors hope this paper could be a modest spur to induce others in basic research in earthquake forecast and prediction.

Exploring E Turkey: Rainfall Precursor Predicts 100% Earthquake in a Consistent Manner in Just 2 Weeks

Rainfall event is the very specific, reliable unambiguous precursor for the earthquake event. Over the years scientists have hunted for some signal—a precursory sign, however faint—that would allow forecasters to pin-point exactly where and when the big ones will hit. After decades spent searching in vain, many seismologists now doubt whether such a signal even exists. But in a great surprise to everyone, from an ordinary lay man to eminent scientists, 100% earthquakes occur after rainfalls! Though I have the findings for the entire regions of the world, here E Turkey are the region for submission for the period Jan-November, 2012 to study the strong correlation and show the strong evidence to prove that the 100% earthquakes after rainfall in a consistence manner. Anyone can very easily verify the validity of the findings for any forthcoming earthquakes for any regions of E Turkey in just two weeks of period. Nature does not give two different results for the same phenomena, for two different observers. Though there exists a very strong relation between the rainfalls and the earthquakes, scientists and seismologists have not been able to detect and identify this rainfall precursory signal for hundreds of years that consistently occurs before earthquakes. The methodology of rainfall event before earthquakes, even works consistently for earthquake prediction purpose, especially in any regions of the world. Rainfall type precursor is the best approach to predict specific earthquakes, which provide the potential for estimating the epicenter and magnitude of any moderate to strong earthquakes. Earthquakes are more likely when there is rain than it is not. The magnitudes of a resulting individual earthquake depend on the severity of the weather changes. However, in a very few cases the time scales and magnitude do vary substantially as a consequence of local site geology and other factors.

Analysis on Depth Distribution and Precursor Mechanism of Small and Moderate Earthquakes

In this paper, the focus depth distribution of earthquakes with each magnitude has been analyzed. Statistic data show that the lower magnitude is, the wider focus depth distributes. With larger magnitude, the focus tends to be concentrated in upper or middle crustal layers. We analyzed the cause of focus depth distribution and explained the precursor mechanism of small and moderate earthquakes with occurring condition and characteristics of strong earthquakes. The results of this paper may be applied to determine risk sites of strong earthquakes.

Dynamic Evolution of Precursory Field and Its Relation With the Group of Strong Earthquakes

Spatial scanning is done for two regions in Chinese Mainland,where displayed a denseprecursory network during 1994～1998.The two regions are the mid-southern segment of theNorth-south seismic belt(20°～35°N,95°～110°E)and North China(36°～42°N,110°～120°E).We took 0.5°×0.5°as a spatial window with a step of 0.25°and 4 months as atemporal window with a step of 1 month.For the two regions,the anomaly density is scannedfrom 1994 and 1995 respectively in the two regions.The precursory anomalies are all fromthe Division of Seismic Trend in China and the Division of Seismic Trend in the Capital Area,Center for Analysis and Prediction,China Seismological Bureau.A seismogenic tectonicmodel is introduced to explain the scanning results.In the model,the frictional strength ofthe focal sources is distributed randomly.After the boundary plate motion rate and all othergeological parameters are given,the stress of the sources in the system changesinhomogenously due to the variation of the frictional

Temporal variation of gravity field before and after Wenchuan Ms8.0 earthquake

Absolute and relative gravity data during 1998 to 2008 were used to study gravity field and temporal variation in the North-South seismic-belt region, and their correlation with seismic activities before and after Wenchuan Ms8.0 earthquake. The temporal variation of gravity field shows that the portentous information of the gravity field reflects the development and occurrence of earthquake more clearly. The variations of gravity field are inhomogeneous in the space-time distribution, and are associated with the development and occurrence of the Wenchuan Ms8.0 earthquake, also closely connected with active fault tectonics.

Pre-seismic and Co-seismic Crustal Movements of the M 7.3 Kyushu Earthquake on April 16,2016 in Japan

The time series of coordinates of a large number of GPS stations in the world,processed by Prof. Geoffrey Blewitt with GIPSY software are available at http://geodesy. unr. edu.Based on the time series of coordinates in the global reference frame of IGS08 at more than250 stations of continuous GPS observations,downloaded from the website,the co-seismic displacements of the M7. 3 Kyushu earthquake on April 16,2016 in Japan and the preseismic strain accumulations and displacements in the regional reference frame were obtained. The station of continuous GPS observation at BJFS near Beijing has been quite stable in displacement in the eastern part of China for more than 17 years since the beginning of its operation,and this station is used as the core station in the regional reference frame for the pre-seismic displacement of the Kyushu earthquake of M7. 3. The main feature of the pre-seismic displacements of the Kyushu earthquake is characterized by locking in the crust at and near the epicenter. The anomalous pre-seismic strain accumulation developed in an area of anomalous accumulation of the shear strain component of γ1 on the northeast side of the epicenter,with increasing size of the area and increasing magnitude in γ1. The largest area covered by the anomalous γ1 is about 2000 km2. The change in the E component at BJFS since November 26,2015 was caused by the replacement of the receiver and the antenna at the station. In order to study the shortterm change in displacements at stations at and near the epicenter,the time series at 3 stations with continuous GPS observations,2 at SUWN and DAEJ in south Korea and 1 at BJSH near Beijing were analyzed. The analysis shows that the displacements at the 3 stations have been quite stable in the same manner in east Asia. Thus,BJSH is used as the core station in the regional reference frame of displacement and the displacement time series show that there were no significant short term anomalies before the earthquake.

Determining the Epicenter of a Future Short-Focus Earthquake Tens of Hours before Earthquake and Reducing the Magnitude of an Impending Catastrophic Earthquake

The article describes a project proposed to determine the epicenter of a future short-focus earthquake tens of hours before and to reduce the magnitude of an impending catastrophic earthquake. It focuses on developing a physical model to determine the conditions necessary for the start of an earthquake, for a method based on the registration of flows of mercury vapor in the gas rising from the Earth. This model gives an explanation of why an earthquake precursor appears so early (such a long period of time can range from a few to hundreds of hours). Normally, the characteristic times of an earthquake precursor for seismic methods are tens of seconds. The project is based on the physical and mathematical models of an earthquake. The derived formula for the time of the precursor of a future earthquake allows us to explain and to describe the time increase for the precursor, depending on the magnitude of the earthquake. The method of reducing the magnitude of an impending catastrophic earthquake is based on the proposed physical model of the onset of an earthquake and is implemented by the action of a vibration source in the region of the detected earthquake epicenter. The proposed system should save citizens, lives from future short-focus earthquakes.