Hojjat Kaveh, Pau Batlle, M. Acosta, Pranav Kulkarni, S. J. Bourne, J. Avouac
Reservoir operations for gas extraction, fluid disposal, carbon dioxide storage, or geothermal energy production are capable of inducing seismicity. Modeling tools exist for seismicity forecasting using operational data, but the computational costs and uncertainty quantification (UQ) pose challenges. We address this issue in the context of seismicity induced by gas production from the Groningen gas field using an integrated modeling framework, which combines reservoir modeling, geomechanical modeling, and stress-based earthquake forecasting. The framework is computationally efficient thanks to a 2D finite-element reservoir model, which assumes vertical flow equilibrium, and the use of semianalytical solutions to calculate poroelastic stress changes and predict seismicity rate. The earthquake nucleation model is based on rate-and-state friction and allows for an initial strength excess so that the faults are not assumed initially critically stressed. We estimate uncertainties in the predicted number of earthquakes and magnitudes. To reduce the computational costs, we assume that the stress model is true, but our UQ algorithm is general enough that the uncertainties in reservoir and stress models could be incorporated. We explore how the selection of either a Poisson or a Gaussian likelihood influences the forecast. We also use a synthetic catalog to estimate the improved forecasting performance that would have resulted from a better seismicity detection threshold. Finally, we use tapered and nontapered Gutenberg–Richter distributions to evaluate the most probable maximum magnitude over time and account for uncertainties in its estimation. Although we did not formally account for uncertainties in the stress model, we tested several alternative stress models, and found negligible impact on the predicted temporal evolution of seismicity and forecast uncertainties. Our study shows that the proposed approach yields realistic estimates of the uncertainties of temporal seismicity and is applicable for operational forecasting or induced seismicity monitoring. It can also be used in probabilistic traffic light systems.
{"title":"Induced Seismicity Forecasting with Uncertainty Quantification: Application to the Groningen Gas Field","authors":"Hojjat Kaveh, Pau Batlle, M. Acosta, Pranav Kulkarni, S. J. Bourne, J. Avouac","doi":"10.1785/0220230179","DOIUrl":"https://doi.org/10.1785/0220230179","url":null,"abstract":"\u0000 Reservoir operations for gas extraction, fluid disposal, carbon dioxide storage, or geothermal energy production are capable of inducing seismicity. Modeling tools exist for seismicity forecasting using operational data, but the computational costs and uncertainty quantification (UQ) pose challenges. We address this issue in the context of seismicity induced by gas production from the Groningen gas field using an integrated modeling framework, which combines reservoir modeling, geomechanical modeling, and stress-based earthquake forecasting. The framework is computationally efficient thanks to a 2D finite-element reservoir model, which assumes vertical flow equilibrium, and the use of semianalytical solutions to calculate poroelastic stress changes and predict seismicity rate. The earthquake nucleation model is based on rate-and-state friction and allows for an initial strength excess so that the faults are not assumed initially critically stressed. We estimate uncertainties in the predicted number of earthquakes and magnitudes. To reduce the computational costs, we assume that the stress model is true, but our UQ algorithm is general enough that the uncertainties in reservoir and stress models could be incorporated. We explore how the selection of either a Poisson or a Gaussian likelihood influences the forecast. We also use a synthetic catalog to estimate the improved forecasting performance that would have resulted from a better seismicity detection threshold. Finally, we use tapered and nontapered Gutenberg–Richter distributions to evaluate the most probable maximum magnitude over time and account for uncertainties in its estimation. Although we did not formally account for uncertainties in the stress model, we tested several alternative stress models, and found negligible impact on the predicted temporal evolution of seismicity and forecast uncertainties. Our study shows that the proposed approach yields realistic estimates of the uncertainties of temporal seismicity and is applicable for operational forecasting or induced seismicity monitoring. It can also be used in probabilistic traffic light systems.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"9 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139000127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The 2023 Mw 7.8 Türkiye earthquake caused severe damage in near-fault regions. The broadband source model, which is important for predicting strong motions in near-fault regions, was estimated. First, high-frequency (3–10 Hz) source imaging was performed through isochrone backprojection using near-field strong-motion records. Four segments were set, consisting of three segments along the East Anatolian fault and one segment along the splay fault where the rupture started. The estimated rupture velocities at the four segments were 2.6–3.3 km/s. The broadband (0.2–10 Hz) source model was then estimated using the empirical Green’s function method. The locations of eight strong-motion generation areas (SMGAs) of the broadband source model were searched with reference to the large brightness area estimated by isochrone backprojection. The source parameters of the SMGAs were estimated to fit the calculated acceleration and velocity envelopes at 21 strong-motion stations to the observed ones. The locations of the SMGAs were mostly consistent with the large slip area estimated by previous studies from long-period waveforms or static data, except for one SMGA with the highest Brune’s stress drop on the splay fault. The highest stress drop caused large ground motions near the splay fault, for which the supershear rupture has been suggested by previous studies. Ground motions were reproduced except for some stations affected by the fling-steps or nonlinear site effects. Although the SMGAs were not located near the southern side of the southwestern segment in Hatay Province, the large ground motions at shorter than about 2 s were mostly simulated. Large empirical site amplification factors estimated in this study must play a role on the large ground motions. The forward rupture directivity effects, with a rupture velocity of 3.3 km/s as large as the S-wave velocity, were also responsible for the large ground motions there.
{"title":"Broadband Source Model of the 2023 Mw 7.8 Türkiye Earthquake from Strong-Motion Records by Isochrone Backprojection and Empirical Green’s Function Method","authors":"T. Satoh","doi":"10.1785/0220230268","DOIUrl":"https://doi.org/10.1785/0220230268","url":null,"abstract":"\u0000 The 2023 Mw 7.8 Türkiye earthquake caused severe damage in near-fault regions. The broadband source model, which is important for predicting strong motions in near-fault regions, was estimated. First, high-frequency (3–10 Hz) source imaging was performed through isochrone backprojection using near-field strong-motion records. Four segments were set, consisting of three segments along the East Anatolian fault and one segment along the splay fault where the rupture started. The estimated rupture velocities at the four segments were 2.6–3.3 km/s. The broadband (0.2–10 Hz) source model was then estimated using the empirical Green’s function method. The locations of eight strong-motion generation areas (SMGAs) of the broadband source model were searched with reference to the large brightness area estimated by isochrone backprojection. The source parameters of the SMGAs were estimated to fit the calculated acceleration and velocity envelopes at 21 strong-motion stations to the observed ones. The locations of the SMGAs were mostly consistent with the large slip area estimated by previous studies from long-period waveforms or static data, except for one SMGA with the highest Brune’s stress drop on the splay fault. The highest stress drop caused large ground motions near the splay fault, for which the supershear rupture has been suggested by previous studies. Ground motions were reproduced except for some stations affected by the fling-steps or nonlinear site effects. Although the SMGAs were not located near the southern side of the southwestern segment in Hatay Province, the large ground motions at shorter than about 2 s were mostly simulated. Large empirical site amplification factors estimated in this study must play a role on the large ground motions. The forward rupture directivity effects, with a rupture velocity of 3.3 km/s as large as the S-wave velocity, were also responsible for the large ground motions there.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"20 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139005232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jongwon Han, Keun Joo Seo, Seongryong Kim, Dong-Hoon Sheen, Donghun Lee, Ah-Hyun Byun
A seismicity catalog spanning 2012–2021 is proposed for the inland and near-coastal areas of the southern Korean Peninsula (SKP). Using deep learning (DL) techniques combined with conventional methods, we developed an integrated framework for compiling a comprehensive seismicity catalog. The proposed DL-based framework allowed us to process, within a week, a large volume of data (spanning 10 yr) collected from more than 300 seismic stations. To improve the framework’s performance, a DL picker (i.e., EQTransformer) was retrained using the local datasets from the SKP combined with globally obtained data. A total of 66,858 events were detected by phase association using a machine learning algorithm, and a DL-based event discrimination model classified 29,371 events as natural earthquakes. We estimate source information more precisely using newly updated parameters for locations (a 1D velocity model and station corrections related to the location process) and magnitudes (a local magnitude equation) based on data derived from the application of the DL picker. Compared with a previous catalog, the proposed catalog exhibited improved statistical completeness, detecting 21,475 additional earthquakes. With the newly detected and located earthquakes, we observed the relative low seismicity in the northern SKP, and the linear trends of earthquakes striking northeast–southwest (NE–SW) and northwest–southeast (NW–SE) with a near-right angle between them. In particular, the NE–SW trend corresponds to boundaries of major tectonic regions in the SKP that potentially indicates the development of fault structures along the boundaries. The two predominant trends slightly differ to the suggested optimal fault orientations, implying more complex processes of preexisting geological structures. This study demonstrates the effectiveness of the DL-based framework in analyzing large datasets and detecting many microearthquakes in seismically inactive regions, which will advance our understanding of seismotectonics and seismic hazards in stable continental regions.
{"title":"Research Catalog of Inland Seismicity in the Southern Korean Peninsula from 2012 to 2021 Using Deep Learning Techniques","authors":"Jongwon Han, Keun Joo Seo, Seongryong Kim, Dong-Hoon Sheen, Donghun Lee, Ah-Hyun Byun","doi":"10.1785/0220230246","DOIUrl":"https://doi.org/10.1785/0220230246","url":null,"abstract":"\u0000 A seismicity catalog spanning 2012–2021 is proposed for the inland and near-coastal areas of the southern Korean Peninsula (SKP). Using deep learning (DL) techniques combined with conventional methods, we developed an integrated framework for compiling a comprehensive seismicity catalog. The proposed DL-based framework allowed us to process, within a week, a large volume of data (spanning 10 yr) collected from more than 300 seismic stations. To improve the framework’s performance, a DL picker (i.e., EQTransformer) was retrained using the local datasets from the SKP combined with globally obtained data. A total of 66,858 events were detected by phase association using a machine learning algorithm, and a DL-based event discrimination model classified 29,371 events as natural earthquakes. We estimate source information more precisely using newly updated parameters for locations (a 1D velocity model and station corrections related to the location process) and magnitudes (a local magnitude equation) based on data derived from the application of the DL picker. Compared with a previous catalog, the proposed catalog exhibited improved statistical completeness, detecting 21,475 additional earthquakes. With the newly detected and located earthquakes, we observed the relative low seismicity in the northern SKP, and the linear trends of earthquakes striking northeast–southwest (NE–SW) and northwest–southeast (NW–SE) with a near-right angle between them. In particular, the NE–SW trend corresponds to boundaries of major tectonic regions in the SKP that potentially indicates the development of fault structures along the boundaries. The two predominant trends slightly differ to the suggested optimal fault orientations, implying more complex processes of preexisting geological structures. This study demonstrates the effectiveness of the DL-based framework in analyzing large datasets and detecting many microearthquakes in seismically inactive regions, which will advance our understanding of seismotectonics and seismic hazards in stable continental regions.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"129 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139004377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. O. Salvage, David W. Eaton, Carolyn M. Furlong, Jan Dettmer, Per K. Pedersen
Based on information available at the time, several questionnaire-based schemes have been developed to provide a qualitative assessment of whether a specific earthquake (or earthquake sequence) was likely induced by anthropogenic activities or is inferred to be natural. From a pragmatic perspective, the value of this assessment is arguably the greatest in the immediate aftermath of an event (hours to days), because it could then better serve to guide regulatory response. However, necessary information is often incomplete or uncertain, and there remains a lack of scientific consensus on the most distinctive attributes of induced (vs. natural) earthquake sequences. We present a case study of the Mw 5.2 Peace River earthquake sequence (Alberta, Canada), evaluated using two published frameworks for origin interpretation. The Alberta Energy Regulator initially considered the sequence to be natural, but a study published ~4 mo later came to the opposite interpretation. Prior to this publication, we convened a panel of experts who completed questionnaires as set out by the frameworks; results using both schemes indicate that experts believe the sequence was likely induced. Based on these expert responses, we critically evaluate information that was available publicly in the weeks to months following the mainshock on 30 November 2022; reassess the relative importance of various components of the questionnaires from a parsimonious, rapid-response perspective; and consider other types of information that could be critical for near-real-time assessment of whether an event was induced or natural.
{"title":"Induced or Natural? Toward Rapid Expert Assessment, with Application to the Mw 5.2 Peace River Earthquake Sequence","authors":"R. O. Salvage, David W. Eaton, Carolyn M. Furlong, Jan Dettmer, Per K. Pedersen","doi":"10.1785/0220230289","DOIUrl":"https://doi.org/10.1785/0220230289","url":null,"abstract":"\u0000 Based on information available at the time, several questionnaire-based schemes have been developed to provide a qualitative assessment of whether a specific earthquake (or earthquake sequence) was likely induced by anthropogenic activities or is inferred to be natural. From a pragmatic perspective, the value of this assessment is arguably the greatest in the immediate aftermath of an event (hours to days), because it could then better serve to guide regulatory response. However, necessary information is often incomplete or uncertain, and there remains a lack of scientific consensus on the most distinctive attributes of induced (vs. natural) earthquake sequences. We present a case study of the Mw 5.2 Peace River earthquake sequence (Alberta, Canada), evaluated using two published frameworks for origin interpretation. The Alberta Energy Regulator initially considered the sequence to be natural, but a study published ~4 mo later came to the opposite interpretation. Prior to this publication, we convened a panel of experts who completed questionnaires as set out by the frameworks; results using both schemes indicate that experts believe the sequence was likely induced. Based on these expert responses, we critically evaluate information that was available publicly in the weeks to months following the mainshock on 30 November 2022; reassess the relative importance of various components of the questionnaires from a parsimonious, rapid-response perspective; and consider other types of information that could be critical for near-real-time assessment of whether an event was induced or natural.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"128 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139004379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dynamic rupture simulations generate synthetic waveforms that account for nonlinear source and path complexity. Here, we analyze millions of spatially dense waveforms from 3D dynamic rupture simulations in a novel way to illuminate the spectral fingerprints of earthquake physics. We define a Brune-type equivalent near-field corner frequency (fc) to analyze the spatial variability of ground-motion spectra and unravel their link to source complexity. We first investigate a simple 3D strike-slip setup, including an asperity and a barrier, and illustrate basic relations between source properties and fc variations. Next, we analyze >13,000,000 synthetic near-field strong-motion waveforms generated in three high-resolution dynamic rupture simulations of real earthquakes, the 2019 Mw 7.1 Ridgecrest mainshock, the Mw 6.4 Searles Valley foreshock, and the 1992 Mw 7.3 Landers earthquake. All scenarios consider 3D fault geometries, topography, off-fault plasticity, viscoelastic attenuation, and 3D velocity structure and resolve frequencies up to 1–2 Hz. Our analysis reveals pronounced and localized patterns of elevated fc, specifically in the vertical components. We validate such fc variability with observed near-fault spectra. Using isochrone analysis, we identify the complex dynamic mechanisms that explain rays of elevated fc and cause unexpectedly impulsive, localized, vertical ground motions. Although the high vertical frequencies are also associated with path effects, rupture directivity, and coalescence of multiple rupture fronts, we show that they are dominantly caused by rake-rotated surface-breaking rupture fronts that decelerate due to fault heterogeneities or geometric complexity. Our findings highlight the potential of spatially dense ground-motion observations to further our understanding of earthquake physics directly from near-field data. Observed near-field fc variability may inform on directivity, surface rupture, and slip segmentation. Physics-based models can identify “what to look for,” for example, in the potentially vast amount of near-field large array or distributed acoustic sensing data.
{"title":"Equivalent Near-Field Corner Frequency Analysis of 3D Dynamic Rupture Simulations Reveals Dynamic Source Effects","authors":"Nico Schliwa, A. Gabriel","doi":"10.1785/0220230225","DOIUrl":"https://doi.org/10.1785/0220230225","url":null,"abstract":"\u0000 Dynamic rupture simulations generate synthetic waveforms that account for nonlinear source and path complexity. Here, we analyze millions of spatially dense waveforms from 3D dynamic rupture simulations in a novel way to illuminate the spectral fingerprints of earthquake physics. We define a Brune-type equivalent near-field corner frequency (fc) to analyze the spatial variability of ground-motion spectra and unravel their link to source complexity. We first investigate a simple 3D strike-slip setup, including an asperity and a barrier, and illustrate basic relations between source properties and fc variations. Next, we analyze >13,000,000 synthetic near-field strong-motion waveforms generated in three high-resolution dynamic rupture simulations of real earthquakes, the 2019 Mw 7.1 Ridgecrest mainshock, the Mw 6.4 Searles Valley foreshock, and the 1992 Mw 7.3 Landers earthquake. All scenarios consider 3D fault geometries, topography, off-fault plasticity, viscoelastic attenuation, and 3D velocity structure and resolve frequencies up to 1–2 Hz. Our analysis reveals pronounced and localized patterns of elevated fc, specifically in the vertical components. We validate such fc variability with observed near-fault spectra. Using isochrone analysis, we identify the complex dynamic mechanisms that explain rays of elevated fc and cause unexpectedly impulsive, localized, vertical ground motions. Although the high vertical frequencies are also associated with path effects, rupture directivity, and coalescence of multiple rupture fronts, we show that they are dominantly caused by rake-rotated surface-breaking rupture fronts that decelerate due to fault heterogeneities or geometric complexity. Our findings highlight the potential of spatially dense ground-motion observations to further our understanding of earthquake physics directly from near-field data. Observed near-field fc variability may inform on directivity, surface rupture, and slip segmentation. Physics-based models can identify “what to look for,” for example, in the potentially vast amount of near-field large array or distributed acoustic sensing data.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"25 13","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138591228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
DBSCAN is a widely used unsupervised machine learning algorithm for clustering and spatial data analysis. However, the accuracy of the algorithm is highly dependent on the selection of its hyperparameters, minimum samples (Smin), the minimum number of points required to form a cluster, and ϵ, the maximum distance between points. In this study, we propose a modification to the DBSCAN algorithm by introducing an event density map replacing Smin and ε. Through this method, we decrease the number of hyperparameters from two to one, N which represents the number of cells in the event density map, simplifying, and speeding up optimization. As a result, the optimization of the algorithm will be improved as the sole factor to consider is the size of each cell. In addition, the utilization of dynamic Smin will provide more effective clustering because it is better suited to regions that have a variable earthquake density. We used the Iranian earthquake catalog for testing the algorithm, and we compared the outcomes to the Mirzaei et al. (1998) model as a standard for evaluation. Because this algorithm allows for density contrasts between clusters, it can be a good indicator when studying the zonation of a new area. The findings were more consistent than those of other methods and may offer additional insight into the seismotectonic of Iran. Other than earthquake studies, this algorithm can be applied in multiple fields of science and engineering for clustering datasets with variable-density clusters.
DBSCAN是一种广泛应用于聚类和空间数据分析的无监督机器学习算法。然而，该算法的准确性高度依赖于其超参数的选择，最小样本(Smin)，形成聚类所需的最小点数，以及点之间的最大距离。在这项研究中，我们提出了一种改进的DBSCAN算法，通过引入一个事件密度图来取代Smin和ε。通过该方法，我们将超参数的数量从2个减少到1个，N代表事件密度图中的单元数，简化了优化过程，加快了优化速度。因此，算法的优化将得到改善，因为唯一要考虑的因素是每个单元的大小。此外，动态Smin的利用将提供更有效的聚类，因为它更适合具有可变地震密度的地区。我们使用伊朗地震目录来测试算法，并将结果与Mirzaei et al.(1998)模型作为评估标准进行了比较。由于该算法允许集群之间的密度对比，因此在研究新区域的分区时，它可以成为一个很好的指标。这些发现比其他方法更加一致，并可能为了解伊朗的地震构造提供额外的见解。除地震研究外，该算法还可以应用于科学和工程的多个领域，用于变密度聚类的数据集聚类。
{"title":"Improved Earthquake Clustering Using a Density-Adaptive DBSCAN Algorithm: An Example from Iran","authors":"Sina Sabermahani, Andrew W. Frederiksen","doi":"10.1785/0220220305","DOIUrl":"https://doi.org/10.1785/0220220305","url":null,"abstract":"\u0000 DBSCAN is a widely used unsupervised machine learning algorithm for clustering and spatial data analysis. However, the accuracy of the algorithm is highly dependent on the selection of its hyperparameters, minimum samples (Smin), the minimum number of points required to form a cluster, and ϵ, the maximum distance between points. In this study, we propose a modification to the DBSCAN algorithm by introducing an event density map replacing Smin and ε. Through this method, we decrease the number of hyperparameters from two to one, N which represents the number of cells in the event density map, simplifying, and speeding up optimization. As a result, the optimization of the algorithm will be improved as the sole factor to consider is the size of each cell. In addition, the utilization of dynamic Smin will provide more effective clustering because it is better suited to regions that have a variable earthquake density. We used the Iranian earthquake catalog for testing the algorithm, and we compared the outcomes to the Mirzaei et al. (1998) model as a standard for evaluation. Because this algorithm allows for density contrasts between clusters, it can be a good indicator when studying the zonation of a new area. The findings were more consistent than those of other methods and may offer additional insight into the seismotectonic of Iran. Other than earthquake studies, this algorithm can be applied in multiple fields of science and engineering for clustering datasets with variable-density clusters.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"12 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138595697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Erratum to An Evaluation of the Timing Accuracy of Global and Regional Seismic Stations and Networks","authors":"Yi Yang, Xiaodong Song, A. Ringler","doi":"10.1785/0220230360","DOIUrl":"https://doi.org/10.1785/0220230360","url":null,"abstract":"","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"36 20","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138597918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicolas Leroy, Martin Vallée, D. Zigone, Barbara Romanowicz, É. Stutzmann, Alessia Maggi, C. Pardo, J. Montagner, M. Bès de Berc, C. Broucke, S. Bonaimé, Geneviève Roult, J. Thore, Armelle Bernard, Michel Le Cocq, O. Sirol, Luis Rivera, J. Lévêque, Michel Cara, Frédérick Pesqueira
The GEOSCOPE observatory (Institut de physique du globe de Paris [IPGP] and École et Observatoire des Sciences de la Terre de Strasbourg, 1982) provides more than four decades of high-quality continuous broadband data to the scientific community. Started in 1982 with only two stations, the network has grown over the years thanks to numerous international partnerships. At present, 34 stations operate in 18 countries across all continents and on islands throughout the oceans, filling important gaps in global Earth coverage. Most of the first installed stations are still running today, allowing for long-term observations, and new sites are being prospected to further improve global coverage. Over the years, GEOSCOPE has contributed to defining today’s global seismology standards (data format, data quality level, instrumentation requirements), being the French contribution to the international effort for global seismic observations. The stations are instrumented with the best quality seismometers (from the very first STS-1 in the early 80s to the last STS-6A and Trillium T360 today) and digitizers (Q330HR and Centaur) to record with high fidelity the ground motions generated by all types of seismic sources. Real-time data are sent to the tsunami warning centers and both validated and real-time data are available at the IPGP, Epos-France and Earthscope data centers. The quality of GEOSCOPE data and metadata is ensured by daily and yearly validation that enables issue detection and mitigation. GEOSCOPE, in collaboration with the other global networks, has played and continues to play a crucial role in the study of Earth’s structure and global dynamics and the characterization of all types of seismic sources.
GEOSCOPE天文台(巴黎地球物理研究所[IPGP]和École et Observatoire des Sciences de la Terre de Strasbourg, 1982年)为科学界提供了40多年的高质量连续宽带数据。1982年开始时只有两个电台，由于众多的国际合作伙伴关系，该网络多年来不断发展壮大。目前，34个台站在各大洲的18个国家和各大洋的岛屿上开展业务，填补了全球地球覆盖的重要空白。大多数第一批安装的站点今天仍在运行，可以进行长期观测，并且正在寻找新的站点以进一步改善全球覆盖范围。多年来，GEOSCOPE为定义当今的全球地震学标准(数据格式，数据质量水平，仪器要求)做出了贡献，这是法国对全球地震观测国际努力的贡献。这些台站配备了最优质的地震仪(从80年代初的第一个STS-1到今天的最后一个STS-6A和Trillium T360)和数字化仪(Q330HR和Centaur)，以高保真度记录所有类型震源产生的地面运动。实时数据被发送到海啸预警中心，IPGP、Epos-France和Earthscope数据中心都可以获得验证数据和实时数据。GEOSCOPE数据和元数据的质量通过每日和每年的验证得到保证，从而能够发现和缓解问题。GEOSCOPE与其他全球网络合作，在研究地球结构和全球动力学以及所有类型震源的特征方面已经并将继续发挥关键作用。
{"title":"GEOSCOPE Network: 40 Yr of Global Broadband Seismic Data","authors":"Nicolas Leroy, Martin Vallée, D. Zigone, Barbara Romanowicz, É. Stutzmann, Alessia Maggi, C. Pardo, J. Montagner, M. Bès de Berc, C. Broucke, S. Bonaimé, Geneviève Roult, J. Thore, Armelle Bernard, Michel Le Cocq, O. Sirol, Luis Rivera, J. Lévêque, Michel Cara, Frédérick Pesqueira","doi":"10.1785/0220230176","DOIUrl":"https://doi.org/10.1785/0220230176","url":null,"abstract":"\u0000 The GEOSCOPE observatory (Institut de physique du globe de Paris [IPGP] and École et Observatoire des Sciences de la Terre de Strasbourg, 1982) provides more than four decades of high-quality continuous broadband data to the scientific community. Started in 1982 with only two stations, the network has grown over the years thanks to numerous international partnerships. At present, 34 stations operate in 18 countries across all continents and on islands throughout the oceans, filling important gaps in global Earth coverage. Most of the first installed stations are still running today, allowing for long-term observations, and new sites are being prospected to further improve global coverage. Over the years, GEOSCOPE has contributed to defining today’s global seismology standards (data format, data quality level, instrumentation requirements), being the French contribution to the international effort for global seismic observations. The stations are instrumented with the best quality seismometers (from the very first STS-1 in the early 80s to the last STS-6A and Trillium T360 today) and digitizers (Q330HR and Centaur) to record with high fidelity the ground motions generated by all types of seismic sources. Real-time data are sent to the tsunami warning centers and both validated and real-time data are available at the IPGP, Epos-France and Earthscope data centers. The quality of GEOSCOPE data and metadata is ensured by daily and yearly validation that enables issue detection and mitigation. GEOSCOPE, in collaboration with the other global networks, has played and continues to play a crucial role in the study of Earth’s structure and global dynamics and the characterization of all types of seismic sources.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"61 18","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138605099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Querétaro region (central Mexico) is located in the trans-Mexican volcanic belt, an active volcanic arc related to the subduction of oceanic plates along the Pacific margin of Mexico. It is characterized by north–south-striking normal faults of the southern Basin and Range Province, up to 40 km long and with morphologically pronounced scarps, such as the San Miguel de Allende fault and the faults forming the Querétaro graben. These faults are located directly north of a major regional-scale system of east–west striking, seismically active intra-arc normal faults that are oriented parallel to the axis of the volcanic arc. Where the two orthogonal normal fault systems interfere, the outcrop-scale observations show that the east–west intra-arc fault system overprints the Basin and Range Province structures. Here we document a 1934 earthquake in a region previously not known for seismic activity. Our study is mostly based on an unpublished contemporary dossier preserved at Archivo Histórico del Instituto de Geología de la Universidad Nacional Autónoma de México, a recently inventoried archive that also preserves several unpublished macroseismic and instrumental studies of major Mexican subduction zone earthquakes between 1911 and 1954. A mainshock–aftershock sequence that initiated 14 July 1934 is documented by instrumental recordings at the Tacubaya observatory and by macroseismic observations at ten population centers, ranging in intensity between five and seven on the modified Mercalli scale. Based on the size of the damage area, the intensity magnitude of the mainshock is estimated at 4.8 ± 0.5. Based on the intensity distribution, the epicenter was located in the Laja River valley north-northeast of the town of Celaya, in the south-southwestern extrapolated continuation of the San Miguel de Allende normal fault scarp, which suggests that this fault extends to the epicentral region of the 1934 earthquake and is characterized by recurrent Quaternary tectonic activity.
querimataro地区(墨西哥中部)位于跨墨西哥火山带，这是一条与墨西哥太平洋边缘海洋板块俯冲有关的活火山弧。它的特征是南部盆地和山脉省的南北走向的正断层，长达40公里，具有形态明显的陡崖，如圣米格尔德阿连德断层和形成querimadaro地堑的断层。这些断层位于与火山弧轴线平行的东西向、地震活跃的弧内正断层的主要区域尺度系统的正北。露头尺度观测显示，东西向的弧内断裂体系覆盖了盆地和岭省构造。在这里，我们记录了1934年在一个以前不知道地震活动的地区发生的地震。我们的研究主要基于保存在档案馆Histórico del Instituto de Geología de la Universidad Nacional Autónoma de macimxico的一份未发表的当代档案，这是一份最近编录的档案，其中还保存了一些未发表的关于1911年至1954年墨西哥俯冲带主要地震的宏观地震和仪器研究。塔库巴亚天文台的仪器记录和10个人口中心的宏观地震观测记录了始于1934年7月14日的主震-余震序列，强度在修正的Mercalli震级5到7级之间。根据震区大小，估计主震烈度为4.8±0.5级。根据地震强度分布，震中位于Celaya镇东北偏北的Laja河流域，位于San Miguel de Allende正断层断崖的西南向外推延续性中，表明该断层延伸至1934年地震的震中区域，具有第四纪构造活动频繁的特征。
{"title":"Seismotectonics of the Querétaro Region (Central Mexico) and the 1934 MI 4.8 Earthquake North of Celaya","authors":"Max Suter, Lucero Morelos-Rodríguez","doi":"10.1785/0220230256","DOIUrl":"https://doi.org/10.1785/0220230256","url":null,"abstract":"\u0000 The Querétaro region (central Mexico) is located in the trans-Mexican volcanic belt, an active volcanic arc related to the subduction of oceanic plates along the Pacific margin of Mexico. It is characterized by north–south-striking normal faults of the southern Basin and Range Province, up to 40 km long and with morphologically pronounced scarps, such as the San Miguel de Allende fault and the faults forming the Querétaro graben. These faults are located directly north of a major regional-scale system of east–west striking, seismically active intra-arc normal faults that are oriented parallel to the axis of the volcanic arc. Where the two orthogonal normal fault systems interfere, the outcrop-scale observations show that the east–west intra-arc fault system overprints the Basin and Range Province structures. Here we document a 1934 earthquake in a region previously not known for seismic activity. Our study is mostly based on an unpublished contemporary dossier preserved at Archivo Histórico del Instituto de Geología de la Universidad Nacional Autónoma de México, a recently inventoried archive that also preserves several unpublished macroseismic and instrumental studies of major Mexican subduction zone earthquakes between 1911 and 1954. A mainshock–aftershock sequence that initiated 14 July 1934 is documented by instrumental recordings at the Tacubaya observatory and by macroseismic observations at ten population centers, ranging in intensity between five and seven on the modified Mercalli scale. Based on the size of the damage area, the intensity magnitude of the mainshock is estimated at 4.8 ± 0.5. Based on the intensity distribution, the epicenter was located in the Laja River valley north-northeast of the town of Celaya, in the south-southwestern extrapolated continuation of the San Miguel de Allende normal fault scarp, which suggests that this fault extends to the epicentral region of the 1934 earthquake and is characterized by recurrent Quaternary tectonic activity.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"39 12","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138602537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Historical seismic catalogs of Italy record several instances of pairs or triplets of large earthquakes (Mw>6.7) along the Apennine chain, occurring on the same date or within a short time frame (days or weeks). Some of these events have mesoseismic areas tens of kilometers apart and/or seismogenic structures located more than 1–3 times the fault length away. Although in the case of aligned and/or contiguous faults, their cascading activation can be explained by variations in static Coulomb stress, in the case of distant faults, this mechanism could sometimes be replaced by what is known as dynamic triggering, which is caused by the passage of seismic waves generated by a remote source. In this study, I analyze three significant ancient seismic sequences that occurred in the south-central Apennines, suggesting that the extent of the destructive effects of these earthquakes can be attributed to remote dynamic triggering, causing the activation of different and unrelated seismogenic structures within a specific time frame.
{"title":"Nearly Simultaneous Pairs and Triplets of Historical Destructive Earthquakes with Distant Epicenters in the Italian Apennines","authors":"Paolo Galli","doi":"10.1785/0220230135","DOIUrl":"https://doi.org/10.1785/0220230135","url":null,"abstract":"\u0000 Historical seismic catalogs of Italy record several instances of pairs or triplets of large earthquakes (Mw>6.7) along the Apennine chain, occurring on the same date or within a short time frame (days or weeks). Some of these events have mesoseismic areas tens of kilometers apart and/or seismogenic structures located more than 1–3 times the fault length away. Although in the case of aligned and/or contiguous faults, their cascading activation can be explained by variations in static Coulomb stress, in the case of distant faults, this mechanism could sometimes be replaced by what is known as dynamic triggering, which is caused by the passage of seismic waves generated by a remote source. In this study, I analyze three significant ancient seismic sequences that occurred in the south-central Apennines, suggesting that the extent of the destructive effects of these earthquakes can be attributed to remote dynamic triggering, causing the activation of different and unrelated seismogenic structures within a specific time frame.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"85 18","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138604538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：