Prospects for Jovian seismology with the Lenghu planetary telescope

Jupiter is one of the top priorities for deep space exploration in China and other countries.The structure of Jupiter’s interior,in particular,is a crucial but still unclear scientific topic.This paper discusses current scientific understanding of Jupiter’s interior by summarizing the history of past and current exploration and data analysis.We review recent space-based and ground-based observation methods and analyze their feasibility.To gain new insight into the internal structure of Jupiter,we propose to study Jupiter’s innards by planetary seismology.Ground-based observation,namely the Jupiter Seismologic Interferometer Polarization Imager(SIPI)in Lenghu,will be developed to obtain the Doppler velocity distribution on the surface of Jupiter and identify oscillation signals.Lenghu has observation conditions that are not only exceptional in China but even in the world,capable of providing novel insight into the interior of Jupiter.This will also be the first study in China of the interior of Jupiter using asteroseismology,which has significant implications for China’s plans to explore Jupiter via spacecraft-mounted instruments.

Seismology and Climatology: A Study of Seismological Impacts of Climate Change in Indonesia

Climate change has been a matter of discourse for the last several decades. Much research has been conducted regarding the causes and impacts of climate change around the world. The current research contributes to the knowledge of the influence of climate change on our environment, with emphasis on earthquake occurrences in the region of Indonesia. Using global temperature anomaly as a measure of climate change, and earthquake data in Indonesia for the period 1900-2022, the paper seeks to find a relationship (if any) between the two variables. Statistical methods used include normal distribution analysis, linear regression and correlation test. The results show peculiar patterns in the progression of earthquake occurrences as well as global temperature anomaly occurring in the same time periods. The findings also indicated that the magnitudes of earthquakes remained unaffected by global temperature anomalies over the years. Nonetheless, there appears to be a potential correlation between temperature anomalies and the frequency of earthquake occurrences. As per the results, an increase in temperature anomaly is associated with a higher frequency of earthquakes.

Seismology in the Light of Fundamental Sciences

According to the definition, seismology is a science that studies the processes and causes of seismic phenomena and the structure of the Earth, i.e. a scientific discipline that studies the movement of blocks of rocks of the Earth’s crust and mantle and related phenomena. Seismology conducts research in the following areas and is designed to scientifically explain two main issues: 1) Study of the nature of seismic phenomena and the internal structure of the Earth. Why, how and where do seismic impacts occur? 2) Protecting humanity from the catastrophic consequences of seismic events. Is it possible to predict seismic impacts? Like any other scientific discipline, seismology is obliged to follow the laws of science and its fundamental principles. This article is devoted to the description of violations of the fundamental laws of science committed by seismologists in the study of seismic processes and raises the question of compliance of the stated research directions with the current level of development of sciences. Answering point No. 1, regarding the structure of the Earth, it is possible to recognize some successes of seismology, which nevertheless cause great doubts in the scientific community of geophysicists, because if the stratigraphic data of ultra-deep wells often refute [1] the conclusions made by seismologists on the structure of the Earth’s crust at shallow depth, then to assert something unambiguously about the structure of the mantle and at the present stage, seismology cannot. Answering the main questions of seismology, why seismic phenomena occur, and how earthquake energy is formed, seismologists have not had, and have not. Answering point No. 2, we can confidently say that in the matter of forecasting seismic phenomena, seismology has not advanced one iota over the past century, and as seismologists have been confused in the search for earthquake prediction algorithms, they are also confused without any hope of success. All that modern seismology can “boast” is the theory of Elastic recoil [2], the absurdity of which does not cause any doubt among the progressive part of geophysicists. But, the fact that most of the leading scientists-seismologists continue to piously believe the conclusions of the Elastic Recoil theory puts seismology in a humiliating position, because Mr. Reid’s theory is the clearest example of a false theory based on scientific incompetence of scientists, a model of brazen violation of the fundamental laws of science and the foundation of false and ignorant conclusions. Based on the results achieved, or rather on their absence, we regret to draw a sad conclusion: modern seismology is in the deepest decline, the cause of which is the incompetence of researchers as a result of their catastrophically low level of academic training, who stuff the scientific community with scientific geophysical rubbish, breeding similar ignoramuses in seismology. We understand that by asserting this, we offend most seismologists, but it is impossible to continue to tolerate this state of affairs in geophysics, because: “Amicus plato, sed magis amica est veritas.” Obviously, the time has come for a new meteorologist, Alfred Wagener [3], who will come and teach seismologists not to guess on coffee grounds, but to investigate seismic processes using the fundamental laws of science. In this article, we not only investigate the reasons for the unsatisfactory state of affairs in seismology, but also give our answers to the questions, of why earthquakes occur and how seismic energy is formed.

Forensic Seismology and Boundary Element Method Application vis-à-vis ROKS Cheonan Underwater Explosion

On March 26,2010 an underwater explosion(UWE)led to the sinking of the ROKS Cheonan.The official Multinational Civilian-Military Joint Investigation Group(MCMJIG)report concluded that the cause of the underwater explosion was a 250 kg net explosive weight(NEW)detonation at a depth of 6 9 m from a DPRK"CHT-02D"torpedo.Kim and Gitterman(2012a)determined the NEW and seismic magnitude as 136 kg at a depth of approximately 8m and 2.04,respectively using basic hydrodynamics based on theoretical and experimental methods as well as spectral analysis and seismic methods.The purpose of this study was to clarify the cause of the UWE via more detailed methods using bubble dynamics and simulation of propellers as well as forensic seismology.Regarding the observed bubble pulse period of 0.990 s,0.976 s and 1.030 s were found in case of a 136NEW at a detonation depth of 8 m using the boundary element method(BEM)and 3D bubble shape simulations derived for a 136kg NEW detonation at a depth of 8 m approximately 5 m portside from the hull centerline.Here we show through analytical equations,models and 3D bubble shape simulations that the most probable cause of this underwater explosion was a 136 kg NEW detonation at a depth of 8m attributable to a ROK littoral"land control"mine(LCM).

Ultrafast quasi-three-dimensional imaging

Understanding laser induced ultrafast processes with complex three-dimensional(3D)geometries and extreme property evolution offers a unique opportunity to explore novel physical phenomena and to overcome the manufacturing limitations.Ultrafast imaging offers exceptional spatiotemporal resolution and thus has been considered an effective tool.However,in conventional single-view imaging techniques,3D information is projected on a two-dimensional plane,which leads to significant information loss that is detrimental to understanding the full ultrafast process.Here,we propose a quasi-3D imaging method to describe the ultrafast process and further analyze spatial asymmetries of laser induced plasma.Orthogonally polarized laser pulses are adopted to illuminate reflection-transmission views,and binarization techniques are employed to extract contours,forming the corresponding two-dimensional matrix.By rotating and multiplying the two-dimensional contour matrices obtained from the dual views,a quasi-3D image can be reconstructed.This successfully reveals dual-phase transition mechanisms and elucidates the diffraction phenomena occurring outside the plasma.Furthermore,the quasi-3D image confirms the spatial asymmetries of the picosecond plasma,which is difficult to achieve with two-dimensional images.Our findings demonstrate that quasi-3D imaging not only offers a more comprehensive understanding of plasma dynamics than previous imaging methods,but also has wide potential in revealing various complex ultrafast phenomena in related fields including strong-field physics,fluid dynamics,and cutting-edge manufacturing.

Artificial intelligence in seismology:Advent,performance and future trends

Realistically predicting earthquake is critical for seismic risk assessment,prevention and safe design of major structures.Due to the complex nature of seismic events,it is challengeable to efficiently identify the earthquake response and extract indicative features from the continuously detected seismic data.These challenges severely impact the performance of traditional seismic prediction models and obstacle the development of seismology in general.Taking their advantages in data analysis,artificial intelligence(AI) techniques have been utilized as powerful statistical tools to tackle these issues.This typically involves processing massive detected data with severe noise to enhance the seismic performance of structures.From extracting meaningful sensing data to unveiling seismic events that are below the detection level,AI assists in identifying unknown features to more accurately predicting the earthquake activities.In this focus paper,we provide an overview of the recent AI studies in seismology and evaluate the performance of the major AI techniques including machine learning and deep learning in seismic data analysis.Furthermore,we envision the future direction of the AI methods in earthquake engineering which will involve deep learning-enhanced seismology in an internet-of-things(IoT) platform.

Converted-wave Seismology in Anisotropic Media Revisited, Part II: Application to Parameter Estimation

In transversely isotropic media with a vertical symmetry axis （VTI）, the converted-wave （C-wave） moveout over intermediate-to-far offsets is determined by four parameters. These are the C-wave stacking velocity Vc2 , the vertical and effective velocity ratios γ0 and γeff, and the anisotropic parameter χeff. We refer to the four parameters as the C-wave stacking velocity model. The purpose of C-wave velocity analysis is to determine this stacking velocity model. The C-wave stacking velocity model Vc2, γ0, γeff, and χeff can be determined from P-and C-wave reflection moveout data. However, error propagation is a severe problem in C-wave reflection-moveout inversion. The current short-spread stacking velocity as deduced from hyperbolic moveout does not provide sufficient accuracy to yield meaningful inverted values for the anisotropic parameters. The non-hyperbolic moveout over intermediate-offsets （x/z from 1.0 to 1.5） is no longer negligible and can be quantified using a background γ. Non-hyperbolic analysis with a γ correction over the intermediate offsets can yield Vc2 with errors less than 1% for noise free data. The procedure is very robust, allowing initial guesses of γ with up to 20% errors. It is also applicable for vertically inhomogeneous anisotropic media. This improved accuracy makes it possible to estimate anisotropic parameters using 4C seismic data. Two practical work flows are presented for this purpose： the double-scanning flow and the single-scanning flow. Applications to synthetic and real data show that the two flows yield results with similar accuracy but the single-scanning flow is more efficient than the double-scanning flow.

Quasi-Three-Dimensional Cyclotriphosphazene-Based Covalent Organic Framework Nanosheet for Efficient Oxygen Reduction

Metal-free carbon-based materials are considered as promising oxygen reduction reaction(ORR)electrocatalysts for clean energy conversion,and their highly dense and exposed carbon active sites are crucial for efficient ORR.In this work,two unique quasi-three-dimensional cyclotriphosphazene-based covalent organic frameworks(Q3CTP-COFs)and their nanosheets were successfully synthesized and applied as ORR electrocatalysts.The abundant electrophilic structure in Q3CTP-COFs induces a high density of carbon active sites,and the unique bilayer stacking of[6+3]imine-linked backbone facilitates the exposure of active carbon sites and accelerates mass diffusion during ORR.In particular,bulk Q3CTP-COFs can be easily exfoliated into thin COF nanosheets(NSs)due to the weak interlayerπ-πinteractions.Q3CTP-COF NSs exhibit highly efficient ORR catalytic activity(half-wave potential of 0.72 V vs.RHE in alkaline electrolyte),which is one of the best COF-based ORR electrocatalysts reported so far.Furthermore,Q3CTP-COF NSs can serve as a promising cathode for Zn-air batteries(delivered power density of 156 mW cm-2 at 300 mA cm^(-2)).This judicious design and accurate synthesis of such COFs with highly dense and exposed active sites and their nanosheets will promote the development of metal-free carbon-based electrocatalysts.

Preface to the special issue of Dense Array Seismology

Both earthquake seismology and structural seismology rely on observations, which in turn contribute critically to the development of seismology, especially in recent years.In order to understand specific geologic structures and interior processes of the Earth, seismic arrays are widely

Isogeometric nonlocal strain gradient quasi-three-dimensional plate model for thermal postbuckling of porous functionally graded microplates with central cutout with different shapes

This study presents the size-dependent nonlinear thermal postbuckling characteristics of a porous functionally graded material(PFGM) microplate with a central cutout with various shapes using isogeometric numerical technique incorporating nonuniform rational B-splines. To construct the proposed non-classical plate model, the nonlocal strain gradient continuum elasticity is adopted on the basis of a hybrid quasithree-dimensional(3D) plate theory under through-thickness deformation conditions by only four variables. By taking a refined power-law function into account in conjunction with the Touloukian scheme, the temperature-porosity-dependent material properties are extracted. With the aid of the assembled isogeometric-based finite element formulations,nonlocal strain gradient thermal postbuckling curves are acquired for various boundary conditions as well as geometrical and material parameters. It is portrayed that for both size dependency types, by going deeper in the thermal postbuckling domain, gaps among equilibrium curves associated with various small scale parameter values get lower, which indicates that the pronounce of size effects reduces by going deeper in the thermal postbuckling regime. Moreover, we observe that the central cutout effect on the temperature rise associated with the thermal postbuckling behavior in the presence of the effect of strain gradient size and absence of nonlocality is stronger compared with the case including nonlocality in absence of the strain gradient small scale effect.

The application of neural networks to comprehensive prediction by seismology prediction method

BP neural networks is used to mid-term earthquake prediction in this paper. Some usual prediction parameters of seismology are used as the import units of neural networks. And the export units of neural networks is called as the character parameter W_0 describing enhancement of seismicity. We applied this method to space scanning of North China. The result shows that the mid-term anomalous zone of W_0-value usually appeared obviously around the future epicenter 1~3 years before earthquake. It is effective to mid-term prediction.

Radio Anomalies, Acoustic Emissions and Gravitational Variations in the Teaching of Seismology at Secondary School

Following crustal stress and the tectonic evolutions that lead to the triggering of seisms is still premature, for technological reasons. Instead, in view of the energies involved, which are in the order of kilotons, it is necessary to collect symptoms manifesting inside the Earth. The greater the stresses produced, the more evident will be the seismic signals manifesting on a global scale. From the point of view of teaching, it is proposed to study seismology in secondary schools using an ＂evidential＂ paradigm, rather than the ＂Galileian＂ sort. This will require a more modern approach, one that considers non-linearity an investigation model that is more in line with the Natural Science approach. To this effect, also the seismology lab is transformed from a place where reality is ＂reproduced＂, into a setting where comparisons are made in the intrinsic presence of clues rather than proofs. The instruments used to carry out this project, which is taking its first steps in an experimental form in Parma （Italy）, can be reproduced at low cost, but without forsaking precision measurements. The instruments in question are those used to detect radio anomalies, acoustic emissions produced in the deepest layers of the terrestrial crust, and variations in gravity that require a computer to interface data and elaborate signals 24/7.

MODELING v_P AND Q ON EXPLOSION SEISMOLOGY DATA IN NE TIBET

A Sino\|French refraction\|reflection experiment was conducted in October 1998 in the northeastern edge of the Tibetan Plateau from the Qiang Tang through the north Kunlun block.The successive wide\|angle reflection traveltime curves are modeled trying to keep the minimum structure. First results obtained along this 700km transect, show the contrast of crustal structure between the three blocks crossed and the state of the crustal material.North of the Kunlun suture, a change of the Moho depth appears from the Qaidam basin, 55km, to the south approaching the Kunlun range, 65km. But the main crustal characteristic is a great thickness of upper crustal material and the lack of lower crust. This implies a crustal average velocity of 6 2km/s, which is much lower than the worldwide average of 6 45km/s. Interpretations of this crustal column may consider, assuming the crust had been normal that while its upper part thickened the lower one was transported away, underthrust to the south or to depth. Alternatively the velocity in the lower crust may have been changed by metamorphism.

My seismology journey with Donald V.Helmberger

My journey on the wiggles with Don started from February 2008,when I got an opportunity to visit the Caltech Seismolab as a visiting PhD student,which was made possible via Dr.Sidao Ni’s recommendation.A previous student of Don,Sidao was a professor at the School of Earth and Space Sciences(ESS)at the University of Science and Technology of China(USTC)at that time.Sidao offered the“Computational Seismology”class at USTC where I learned a lot about the modern developments in seismology.I also met Sidao many times to discuss a wide range of research topics,I believe it is a style he inherited from his experiences with Don and other professors in Seismolab.

Preface to special issue on recent advances in computational seismology and its applications

Computational seismology is a relatively new interdisciplinary field spanning computational techniques in theoretical and observational seismology. It studies numerical methods and their implementation in various theoretical and applied problems in seismology.

The Development of World Data Center for Seismology,Beijing

World Data Center(WDC)for Seismology,Beijing has developed for 20 years in China until this year.The sustained and stable data sharing service system has already taken shape.This article gives an overview of the construction and development of WDC for Seismology,Beijing.It outlines the history,facilities and technical specifications of the center.It also illustrates the data service,the website,and gives a brief description of the perspective.

The accessible seismological dataset of a high-density 2D seismic array along Anninghe fault

The scientific goal of the Anninghe seismic array is to investigate the detailed geometry of the Anninghe fault and the velocity structure of the fault zone.This 2D seismic array is composed of 161 stations forming sub-rectangular geometry along the Anninghe fault,which covers 50 km and 150 km in the fault normal and strike directions,respectively,with~5 km intervals.The data were collected between June 2020 and June 2021,with some level of temporal gaps.Two types of instruments,i.e.QS-05A and SmartSolo,are used in this array.Data quality and examples of seismograms are provided in this paper.After the data protection period ends(expected in June 2024),researchers can request a dataset from the National Earthquake Science Data Center.

一种海上时移地震数据空缺区智能重建方法

时移地震技术作为目前海上剩余油气监测的重要技术之一,可以有效指导油气田开发方案。针对海上时移地震数据采集过程中第二次采集受平台及海底管线影响导致采集的数据出现空缺的问题,首先利用在同一工区两套不同时期采集的地震数据,即早期采集的拖缆地震数据与近期采集的海底节点(ocean bottom node,OBN)地震数据,进行叠前地震数据一致性处理以及叠后全局匹配处理,使其时移差异能有效反映油气开采引起的地震数据变化;再利用神经网络学习上述两套一致性处理后的地震资料非线性映射关系,对大范围连续缺失的OBN地震数据进行数据重建。上述海上时移地震数据空缺区智能重建方法可以有效利用两套数据的相似性恢复缺失的地震数据,同时尽可能地保持时移地震特征,取得了良好的应用效果。

Recent developments in seismological geodesy

With the advanced development of the modern geodetic techniques, the geodetic obser- vations have been proved to be more powerful to uncover the geophysical phenomena, especially the seismic one, than that in the past time. The recent developments and achievements in the seismological geodesy are summarised here. Several popular geodetic techniques, such as high-rate GNSS, InSAR and Satellite Gravimetry, are introduced first to present their recent contributions in studying the seismic deformations. The developments of the joint inversion of the seismic source parameters from multiple observations are then highlighted. Some outlooks in seismological geodesy are presented in the end.