Journal of Seismology最新文献

{"title":"Parametric study of correlation of mainshock-aftershock ground motions based on Copula theory","authors":"Ziyan Wang,&nbsp;Xiaojun Li,&nbsp;Su Chen,&nbsp;Lei Fu,&nbsp;Bin Zhang,&nbsp;Xianwei Liu,&nbsp;Yanjun Zhu","doi":"10.1007/s10950-024-10238-z","DOIUrl":"10.1007/s10950-024-10238-z","url":null,"abstract":"<div><p>This study investigates the impact of aftershocks on hazard assessment and disaster prevention by examining three main characteristics of strong ground motions: amplitude, spectrum, and duration. A total of 6414 accelerograms were compiled from 26 selected mainshock-aftershock events in the Yalong River Basin, China, Japan, and Turkey. The aim is to investigate the correlation between mainshocks and aftershocks using Copula theory and seven representative intensity measures: peak ground acceleration (PGA), cumulative absolute velocity (CAV), peak ground velocity (PGV), Arias intensity, significant duration, mean frequency and predominant frequency of Fourier amplitude spectrum. The findings reveal a moderate to strong non-linear correlation among the seven intensity measures of mainshocks and aftershocks. This non-linear correlation can be effectively captured using Gumbel, Gaussian, and t-Copula functions. Under the conditions of the optimal Copula joint distribution model among the given intensity measures and the mainshock intensity measures, the Copula conditional prediction model for aftershocks accurately reflects the values of aftershock intensity measures. This approach demonstrates the effectiveness of Copula theory in studying the correlation between mainshock and aftershock intensity measures. It offers a novel method for determining aftershock intensity measures and investigating correlations among multivariate random variables.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":"28 5","pages":"1267 - 1291"},"PeriodicalIF":1.6,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physics-based probabilistic seismic hazard assessment using synthetic ground motions: application to the stable continental region of India","authors":"K. P. Sreejaya,&nbsp;Bhargavi Podili,&nbsp;S. T. G. Raghukanth","doi":"10.1007/s10950-024-10236-1","DOIUrl":"10.1007/s10950-024-10236-1","url":null,"abstract":"<div><p>Attaining explicit hazard estimates is a challenging task for data sparse regions such as the Peninsular India. Physics based probabilistic seismic hazard analysis (Pb-PSHA) has gained momentum in recent years as a viable solution to this issue. While performing a site-specific analysis in data-sparse regions, instead of incorporating ground motion models (GMMs) from other regions in the hazard methodology, the Pb-PSHA involves obtaining physics-based numerical simulations. In the present study, Pb-PSHA is carried out for the entire southern Peninsular India, with a detailed demonstration for the Kalpakkam site, Tamilnadu. Due to absence of any data on local fault characteristics and past rupture models, simulations are derived using the spectral element method, for several source rupture scenarios. Further, the stochastic seismological model is used to simulate for high frequency (1-100 Hz) ensemble ground motions. Broadband ground motions are then obtained by combining the results from the deterministic model i.e., low frequency (0.01-1 Hz) simulations and the stochastic model. Further, PSHA based on elliptical gridded seismicity is carried out to obtain hazard curves for spectral accelerations. The ensuing uniform hazard response spectra are compared against the outcome of traditional PSHA involving a global GMM. The results indicate that the PGA values obtained from the Pb-PSHA are slightly higher than that of the global GMM-based PSHA.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":"28 5","pages":"1247 - 1265"},"PeriodicalIF":1.6,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic source analysis and directivity of the November 2021 Fin doublet earthquake in southern Iran: challenges and findings","authors":"Elham Sabouri,&nbsp;Zaher Hossein Shomali,&nbsp;Mehrdad Pakzad","doi":"10.1007/s10950-024-10237-0","DOIUrl":"10.1007/s10950-024-10237-0","url":null,"abstract":"<div><p>Studying the source characteristics of doublet or multiple earthquake sequences presents significant challenges in seismology, especially with short time intervals between events. On November 14, 2021, a doublet earthquake (Mw 6.0 and Mw 6.1) occurred near Fin city, southern Iran, within a span of less than two minutes and 10 km apart. We employed the Kinematic Waveform Inversion (KIWI) procedure to determine the point and extended source parameters of these events, using a multistep inversion approach for stable solutions. Our analysis highlighted the directivity of the earthquakes: the first event exhibited bilateral directivity, causing a rupture area that reached the surface, while the second event showed unilateral westward directivity, supported by waveform amplitude differences observed at various stations. This directivity analysis plays an essential role in seismic hazard studies. Our findings regarding the source parameters of these recent doublet earthquakes in the Fin region align well with regional geological trends and fault patterns. However, retrieving the main fault plane for the second earthquake was challenging due to the complexities of the waveform. Moment tensor decomposition revealed significant non-double-couple components for the second event, indicating the complexity inherent in analyzing doublet events. This study underscores the critical role of precise waveform analysis and robust inversion techniques in understanding complex seismic events.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":"28 5","pages":"1229 - 1245"},"PeriodicalIF":1.6,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10950-024-10237-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physically adjusted ground motion prediction equations for induced seismicity at Preston New Road, UK","authors":"Pungky Megasari Suroyo,&nbsp;Jaleena Sunny,&nbsp;Benjamin Edwards","doi":"10.1007/s10950-024-10235-2","DOIUrl":"10.1007/s10950-024-10235-2","url":null,"abstract":"<div><p>Predicting ground motions due to induced seismicity is a challenging task owing to the scarcity of data and heterogeneity of the uppermost crust. Dealing with this requires a thorough understanding of the underlying physics and consideration of inter-site variability. The most common ground motion model used in practice is the parametric ground motion prediction equation (GMPE), of which hundreds exist in the literature. However, relatively few are developed with a focus on induced seismicity. Developing GMPEs that are specific to an appropriate magnitude-distance range (<span>(R &lt; 30)</span> km; <span>(2 le M le 6)</span>) is important for induced seismicity applications. This paper proposes a framework for the development of physically-based GMPEs to provide more accurate and reliable estimates of the potential induced-seismicity ground motion hazard, allowing for better risk assessment and management strategies. To demonstrate this approach, a new set of GMPEs for the 2018-2019 induced seismicity sequence at the Preston New Road (PNR) shale gas site near Blackpool, United Kingdom, is presented. The physically-based GMPE was developed based on a pseudo-finite-fault stochastic ground motion simulation, calibrated with parameters derived from the spectral analysis of weak-motion records from induced seismic events. An optimization-based calibration technique using the area metric (AM) was subsequently performed to calibrate optimal parameters for simulating ground motion at the PNR site. Finally, using a suite of forward simulations for events with <span>(1 le M le 6)</span> recorded at distances up to 30 km, combined with empirical data, a location-specific GMPE was derived through adjustment of an existing model.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":"28 5","pages":"1147 - 1171"},"PeriodicalIF":1.6,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10950-024-10235-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling the unusual 22 November 2020 earthquake (Mw 3.5) in the Nile Delta Hinge Zone: Origin and tectonic implications","authors":"I.F Abu El Nader,&nbsp;Hany M. Hassan,&nbsp;Hazem Badreldin,&nbsp;Adel S. Othman,&nbsp;Ashraf Adly","doi":"10.1007/s10950-024-10233-4","DOIUrl":"10.1007/s10950-024-10233-4","url":null,"abstract":"<div><p>On November 22, 2020, a moment magnitude of Mw 3.5 earthquake struck the highly populated Nile Delta. This event marked the first recorded earthquake in this area. We employed the polarity of P and S wave first motions, as well as SH and SV amplitudes and their respective ratios (SH/P and SV/SH), to constrain the focal mechanism solution. Furthermore, considering Brune's circular source model, kinematic source parameters were estimated through spectral analysis of available and reliable seismic data. The obtained solution reveals an oblique-slip fault mechanism, characterized by strike, dip, and rake angles of 341º, 69º, and -47º, respectively. Additionally, the two fault planes exhibit trends aligned with the E-W and NNW directions. This normal fault mechanism with a strike component aligns with previously identified events in various active areas of Egypt, indicating a dominant extensional stress regime. The trend/plunge of the P and T axes are determined to be 299º/46º and 42º/13º, respectively. Moreover, the NE trending of the T axis agrees well with the current extension stress field prevalent along the eastern border of Egypt. The average seismic moment and moment magnitude values for P and SH waves are estimated to be 1.86 × 10¹⁴ Nm, and 3.5, respectively. Furthermore, the average source values of radius and stress drop are calculated to be 304 m, and 29 bar, respectively. Through a comparative and comprehensive analysis of fault mechanism solutions in the Nile Delta region and its surroundings, we have concluded that the fault structures in the Hinge Zone and Cairo-Suez Shear Zone exhibit similarities. This finding provides evidence that the geodynamic processes and fault style are identical. In conclusion, the provided information contributes to our understanding of the seismotectonic characteristics and earthquake hazard in the epicentral region. Moreover, this study serves as a motivation for future site response and seismic hazard analyses based on a scenario-based approach.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":"28 5","pages":"1205 - 1228"},"PeriodicalIF":1.6,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multimodal quantitative segmental analysis of seismicity of the Zhangjiakou-Bohai tectonic belt (North China)","authors":"Jinmeng Bi,&nbsp;Cheng Song,&nbsp;Fuyang Cao,&nbsp;Yong Ma","doi":"10.1007/s10950-024-10234-3","DOIUrl":"10.1007/s10950-024-10234-3","url":null,"abstract":"<div><p>The purpose of this study is to systematically investigate the segmental seismicity features of the Zhangjiakou-Bohai tectonic belt to understand the characteristics of the seismic activity in this tectonic area and identify potential sources of strong earthquake hazard. From the collected seismic data, we first determined the minimum completeness magnitude by combining qualitative and quantitative methods, such as the detection rate function, maximum curvature (MAXC) method, goodness of fit (GFT) method and magnitude-rank method. We used the stochastic declustering method based on the space-time ETAS model to obtain the background seismicity. We then implemented the accelerating moment release (AMR) model, the Ogata-Katsura 1993 (OK1993) model, the moment ratio (MR) model and the Region-Time-Length (RTL) algorithm. Finally, we analyzed the spatial migration of strong earthquakes. The completeness magnitude of the earthquake sequence does not significantly change with time, with the minimum completeness magnitude being 2.0 for the Zhangjiakou-Bohai tectonic zone. The results provided by the aforementioned seismic activity models allow us to detect some differences between sectors of the tectonic belt. The Zhangjiakou and Tangshan segments show a higher level of seismic hazard compared to the others, which have little chance of a strong earthquake occurring (weak release of seismic energy). The <i>b</i> value of the Zhangjiakou segment shows a stepwise downward trend, reflecting the gradual increase of stress accumulation level, and the hazard of moderate-strong earthquakes is increasing. Compared with the Tangshan and Penglai segments, the Zhangjiakou and Beijing sectors have a slightly higher MR index, which means that the rate of earthquake occurrence is increasing and thus the hazard of moderate to strong earthquakes. According to the RTL value, the deviation of seismic activity in the Zhangjiakou and Tangshan segments is relatively high, and there is a possibility of moderate to strong earthquakes in the future. Based on the results obtained from various seismicity models and the migration law of strong earthquakes, we can say that the overall seismic hazard for each sector of the Zhangjiakou-Bohai tectonic chain is low in terms of qualitative analysis. If anything, the Zhangjiakou segment, which is the section with the relatively high seismic hazard level, should require our attention in the future.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":"28 5","pages":"1309 - 1323"},"PeriodicalIF":1.6,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation of near-fault ground strains and rotations from actual earthquakes with predominantly dip-slip mechanisms","authors":"Yenan Cao,&nbsp;George P. Mavroeidis","doi":"10.1007/s10950-024-10230-7","DOIUrl":"10.1007/s10950-024-10230-7","url":null,"abstract":"<div><p>In the absence of records of near-fault ground strains and rotations from strong earthquakes, deterministic physics-based simulations have become an important tool for characterizing these motions in the low-frequency range (e.g., &lt; 1.0 Hz). Building on a previous study of near-fault ground strains and rotations from actual strike-slip ruptures conducted by the authors, this article investigates the spatial and temporal characteristics of such motions generated by actual earthquakes with predominantly dip-slip mechanisms. This is achieved by performing forward ground-motion simulations of the 1994 <i>M</i>_w 6.7 Northridge, the 1989 <i>M</i>_w 6.9 Loma Prieta, and the 1985 <i>M</i>_w 8.1 Michoacan earthquakes using previously published finite-fault rupture models. For each considered seismic event, time histories of ground strains and rotations are generated at near-fault recording stations and at a dense grid of observation points. This is accomplished by finite differencing translational motions simulated at very closely spaced stations using a kinematic modeling approach. The simulation results show large-amplitude axial strain, shear strain, and rocking in the near-fault region. For the considered earthquakes, the maximum peak ground strain over all grid points is of the order of ~ 100–250 <i>μ</i>strain, whereas the maximum peak ground rocking ranges from ~ 100 to ~ 200 <i>μ</i>rad. The attenuation characteristics of peak ground strains and rotations differ for the considered seismic events and depend on the component of interest and the rupture distance. Finally, peak ground rocking can be reasonably estimated from peak vertical ground velocity using a properly selected scaling factor despite the significant variability of the latter in the near-fault region. Filtering out the very low frequencies of ground motion (&lt; 0.1 Hz), including the static offset, significantly affects the scaling factor.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":"28 4","pages":"1027 - 1053"},"PeriodicalIF":1.6,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of seismic b-value around kopili fault and its neighboring region prior to 28th April 2021 earthquake","authors":"Vickey Sharma,&nbsp;Dipok Kumar Bora,&nbsp;Devajit Hazarika,&nbsp;Rajib Biswas","doi":"10.1007/s10950-024-10232-5","DOIUrl":"10.1007/s10950-024-10232-5","url":null,"abstract":"<div><p>In the present study, the spatio-temporal variation of the seismic b-value in the vicinity of the Kopili fault and its surrounding area has been analysed using the unified and homogenous earthquake catalog of historical and instrumental (1950–2021) earthquake events. The study region is subdivided into 16 equisized square grids of 1° × 1° dimension, and the b-value is computed for each grid using the maximum likelihood method. The spatial distribution of the b-value varies from 0.58 to 1.14. The Kolmogorov–Smirnov (K-S) test has been conducted to check the significance of the spatial-temporal and depth-wise distributions of the b-value. The epicentral location of April 28th, 2021, lies in the low-b-value square grid. Likewise, the temporal b-value curve shows a decreasing trend before the occurrence of the April 28th, 2021 earthquake. The mean return period of the April 28th, 2021earthquake and the most probable maximum annual magnitude earthquake are also computed for this region. Meanwhile, the spatial associations and anomalous patterns between the b-value and factors like seismic moment or energy release and focal depth are assessed, as they contribute to a more comprehensive understanding of the seismicity in this area. The antithetical relationship between the b-value and seismic moment or energy release is established. While variation in b-value with depth provides new insights, low b-values are linked to the top of the crust, which could mean that the crust is uniform and that a lot of stress is building up.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":"28 4","pages":"1001 - 1025"},"PeriodicalIF":1.6,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141746105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revisiting Stepp’s method for the completeness of regional seismic catalogues","authors":"Narsiram Gurjar,&nbsp;Dhiman Basu","doi":"10.1007/s10950-024-10231-6","DOIUrl":"10.1007/s10950-024-10231-6","url":null,"abstract":"<div><p>An important step in seismic hazard analysis is investigating the completeness of available data. Out of the various methods proposed by several researchers, Stepp’s method is one of the most commonly used methods for completeness analysis. Some drawbacks are identified in this method, which results in erroneous estimation of the completeness period. This paper suggests another way of estimation based on the 2-point moving average of the mean annual rate of occurrence of events. The new procedure is able to overcome the problems identified in Stepp’s method and is validated using five catalogues from different regions. The analysis result includes the completeness period determination for different catalogues before and after correction, together with Magnitude-Frequency recurrence relation coefficients compared with Stepp’s method.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":"28 4","pages":"1055 - 1086"},"PeriodicalIF":1.6,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141746106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison between rupture parameters of intermediate and deep earthquakes at the Peru–Brazil–Bolivia border and northern Chile","authors":"Carmen Pro,&nbsp;Hernando Tavera,&nbsp;Maurizio Mattesini,&nbsp;Lucía Escudero,&nbsp;Elisa Buforn,&nbsp;Agustín Udías,&nbsp;Estela Centeno","doi":"10.1007/s10950-024-10229-0","DOIUrl":"10.1007/s10950-024-10229-0","url":null,"abstract":"<div><p>We determined the main parameters of the source rupture process of intermediate- and deep-depth earthquakes occurring in the Peru–Brazil–Bolivia border region and northern Chile. The parameters of depth, fault-plane orientation, scalar seismic moment, slip distribution, and radiated seismic energy are obtained from seismograms. We selected 15 intermediate-depth earthquakes (100 km &lt; h &lt; 300 km) and 10 very deep earthquakes (h &gt; 500 km) with magnitudes M_W ≥ 6.0. For most events, the slip distribution over the rupture plane shows a single asperity, and the source time function presents a simple pulse. There are differences between intermediate-depth and deep earthquakes. The rupture areas, maximum slip and source time function (STF) duration are larger for intermediate-depth events than for deep events. Additionally, the STF’s show a sharper increase for deep earthquakes. The scaled radiated seismic energy shows larger values for deep depth events. The stress regime pattern derived from the obtained focal mechanism agrees with the geometry of the subduction of the Nazca plate. At intermediate depths, in the northern area up to 12°S, the stress pattern corresponds to a horizontal extension, while in the southern area, the tension axes dip at an angle of 30°. At deep depths, the stress regime corresponds to vertical compression in the north and dips of approximately 45° in the south.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":"28 4","pages":"973 - 999"},"PeriodicalIF":1.6,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10950-024-10229-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141570109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}