Seismological Research Letters最新文献_第7页

Earthquakes Parameters from Citizen Testimonies: A Retrospective Analysis of EMSC Database 来自公民证词的地震参数:EMSC数据库的回顾性分析

3区地球科学

Seismological Research Letters Pub Date : 2023-10-30 DOI: 10.1785/0220230245

Gianfranco Vannucci, Paolo Gasperini, Laura Gulia, Barbara Lolli

{"title":"Earthquakes Parameters from Citizen Testimonies: A Retrospective Analysis of EMSC Database","authors":"Gianfranco Vannucci, Paolo Gasperini, Laura Gulia, Barbara Lolli","doi":"10.1785/0220230245","DOIUrl":"https://doi.org/10.1785/0220230245","url":null,"abstract":"Abstract We aim to compute macroseismic parameters (location and magnitude) using the BOXER code for the first time on the citizen testimonies, that is, individual intensity data points (IDPs) at the global scale collected and made available by the LastQuake system of the European–Mediterranean Seismological Centre (EMSC). IDPs available for different earthquakes are selected to eliminate those that are geographically inconsistent with most data; then they are clustered spatially based on various methods. For each cluster with at least three IDPs, a macroseismic data point (MDP), corresponding to an intensity value assessed for given localities as in classical macroseismic studies, is computed by various central tendency estimators (average, median, and trimmed averages). Finally, macroseismic parameters are obtained by MDP distribution using two location methods of BOXER code. For each earthquake, we used raw and corrected intensities and 132 different combinations of grouping methods, estimators, and BOXER methods. We assigned a ranking to the combinations that best reproduce instrumental parameters and used such a ranking to select preferred combinations for each earthquake. We analyzed retrospectively the reliability of the parameters as a function of time and space. The results are essentially identical using original and corrected intensities and show higher reliability for BOXER’s method 1 than for method 0; they are dependent on the geographical area, and generally improve over time and with the number of IDPs collected. These findings are useful for the future real-time analyses, and for evaluating the location and magnitude of earthquakes whenever a sufficient number of IDPs are available and with a distribution such that MDPs can be derived and the BOXER method applied.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"44 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136068343","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}

引用次数: 0

Characterization of Focal Mechanisms for Upper Crustal Distributed Seismicity in Aotearoa New Zealand 新西兰奥特罗阿上地壳分布地震活动性的震源机制表征

3区地球科学

Seismological Research Letters Pub Date : 2023-10-26 DOI: 10.1785/0220230196

Kiran Kumar Singh Thingbaijam, Mark S. Rattenbury, Russ J. Van Dissen, Matt C. Gerstenberger, John Ristau, Delphine D. Fitzenz

引用次数: 1

“Did You Feel It 50 Years Ago?” The 1969 Mw 7.8 Cape Saint Vincent Earthquake “50年前你感觉到了吗?”1969年圣文森特角7.8级地震

3区地球科学

Seismological Research Letters Pub Date : 2023-10-24 DOI: 10.1785/0220230191

Célia Marreiros, Paulo M. Alves, Susana Custódio, Carlos S. Oliveira, Fernando Carrilho

{"title":"“Did You Feel It 50 Years Ago?” The 1969 Mw 7.8 Cape Saint Vincent Earthquake","authors":"Célia Marreiros, Paulo M. Alves, Susana Custódio, Carlos S. Oliveira, Fernando Carrilho","doi":"10.1785/0220230191","DOIUrl":"https://doi.org/10.1785/0220230191","url":null,"abstract":"Abstract On 28 February 1969, an Mw 7.8 earthquake occurred 180 km southwest of Cape Saint Vincent, Portugal. The earthquake was widely felt in mainland Portugal, Madeira Island, Spain, Morocco, and even as far as Andorra and France, reaching a maximum intensity of VIII in the south of Portugal. In 2019, on the 50th anniversary of the earthquake, there was launched online an international “Did You Feel It 50 Years Ago?” (DYFI-50y) survey, published in several languages, for citizens to report the observed effects of the earthquake. This initiative had two main purposes: first, to collect and preserve community observations of the earthquake; and second, to test the online implementation of the DYFI questionnaire at Instituto Português do Mar e da Atmosfera for a damaging event. The DYFI-50y questionnaire was disseminated widely in the media, and a school project was launched for school-age children to collect reports from grandparents or other close elders. In total, more than 3000 reports were collected, a number that is close to the number of reports received for a recent M 6 earthquake in 2009. The collected community reports provide good coverage of mainland Portugal, particularly in Lisbon and Porto’s densely populated urban centers. In low-population areas, the limited results do not allow for robust statistics, and variability becomes significant. The distribution of intensities obtained shows a generally good agreement with other sources, indicating that the community reports are reliable and complement existing intensity maps for this earthquake, further clarifying some of the observed patterns. It was concluded that an online questionnaire is an efficient tool for gathering data several years after the earthquake.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135267478","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}

引用次数: 0

Seismic T Phases in the Western-Central Mediterranean: Source of Seismic Hazard? 地中海中西部地震T相:地震危险源?

3区地球科学

Seismological Research Letters Pub Date : 2023-10-24 DOI: 10.1785/0220220326

Mariagrazia De Caro, Caterina Montuori, Francesco Frugoni, Stephen Monna, Alessandra Giuntini

{"title":"Seismic <i>T</i> Phases in the Western-Central Mediterranean: Source of Seismic Hazard?","authors":"Mariagrazia De Caro, Caterina Montuori, Francesco Frugoni, Stephen Monna, Alessandra Giuntini","doi":"10.1785/0220220326","DOIUrl":"https://doi.org/10.1785/0220220326","url":null,"abstract":"Abstract The Algerian offshore earthquake of 18 March 2021, Mw 6.0, was felt by people in various Italian regions, also at large epicentral distance. This unusual human perception far from the source prompted us to analyze the waveforms recorded by land seismic stations installed along the Iberian, French, and Italian coasts. On some seismograms of the selected network, prominent T phases are detected. T waves can travel in the SOund Fixing And Ranging (SOFAR) channel over great distances (thousands of kilometers) with little loss in signal strength and be recorded by near-coastal seismometers after the P (primary) and S (secondary) phases (hence T or tertiary phases). To explain the subjective perception of ground shaking with quantities that are measured on the seismogram, we estimated the empirical macroseismic intensities for both body and T phases and we calculated the body-wave seismic attenuation. The P-wave anelastic attenuation analysis shows two main wave propagation patterns that reflect lithosphere heterogeneity of the Algerian, Liguro-Provençal, and Tyrrhenian basins. We find that in some cases, in particular along the Italian and French coasts, the largest ground shaking is caused by the T phase. Our observations confirm that the central-western Mediterranean Sea is a favorable site for T-wave propagation and suggest that the T phases should be taken into account in ground-shaking hazard assessment for the central-western Mediterranean.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135273262","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}

引用次数: 0

Fault Source Models Show Slip Rates Measured across the Width of the Entire Fault Zone Best Represent the Observed Seismicity of the Pallatanga–Puna Fault, Ecuador 断层源模型显示沿整个断裂带宽度测量的滑动率最能代表观测到的厄瓜多尔帕拉坦加-普纳断层的地震活动性

3区地球科学

Seismological Research Letters Pub Date : 2023-10-24 DOI: 10.1785/0220230217

Nicolas Harrichhausen, Laurence Audin, Stéphane Baize, Kendra L. Johnson, Céline Beauval, Paul Jarrin, Léo Marconato, Frédérique Rolandone, Hervé Jomard, Jean-Mathieu Nocquet, Alexandra Alvarado, Patricia A. Mothes

{"title":"Fault Source Models Show Slip Rates Measured across the Width of the Entire Fault Zone Best Represent the Observed Seismicity of the Pallatanga–Puna Fault, Ecuador","authors":"Nicolas Harrichhausen, Laurence Audin, Stéphane Baize, Kendra L. Johnson, Céline Beauval, Paul Jarrin, Léo Marconato, Frédérique Rolandone, Hervé Jomard, Jean-Mathieu Nocquet, Alexandra Alvarado, Patricia A. Mothes","doi":"10.1785/0220230217","DOIUrl":"https://doi.org/10.1785/0220230217","url":null,"abstract":"Abstract We explore how variation of slip rates in fault source models affect computed earthquake rates of the Pallatanga–Puna fault system in Ecuador. Determining which slip rates best represent fault-zone seismicity is vital for use in probabilistic seismic hazard assessment (PSHA). However, given the variable spatial and temporal scales slip rates are measured over, significantly different rates can be observed along the same fault. The Pallatanga–Puna fault in southern Ecuador exemplifies a fault where different slip rates have been measured using methods spanning different spatial and temporal scales, and in which historical data and paleoseismic studies provide a record of large earthquakes over a relatively long time span. We use fault source models to calculate earthquake rates using different slip rates and geometries for the Pallatanga–Puna fault, and compare the computed magnitude–frequency distributions (MFDs) to earthquake catalog MFDs from the fault zone. We show that slip rates measured across the entire width of the fault zone, either based on geodesy or long-term geomorphic offsets, produce computed MFDs that compare more favorably with the catalog data. Moreover, we show that the computed MFDs fit the earthquake catalog data best when they follow a hybrid-characteristic MFD shape. These results support hypotheses that slip rates derived from a single fault strand of a fault system do not represent seismicity produced by the entire fault zone.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"2004 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135273070","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}

引用次数: 0

Fireworks: A Potential Artificial Source for Imaging Near-Surface Structures 烟火:近地表结构成像的潜在人工光源

3区地球科学

Seismological Research Letters Pub Date : 2023-10-20 DOI: 10.1785/0220220281

Risheng Chu, Qingdong Wang, Zhigang Peng, Minhan Sheng, Qiaoxia Liu, Haopeng Chen

{"title":"Fireworks: A Potential Artificial Source for Imaging Near-Surface Structures","authors":"Risheng Chu, Qingdong Wang, Zhigang Peng, Minhan Sheng, Qiaoxia Liu, Haopeng Chen","doi":"10.1785/0220220281","DOIUrl":"https://doi.org/10.1785/0220220281","url":null,"abstract":"Abstract Seismic waves induced by incident acoustic waves from air disturbances can be used to image near-surface structures. In this article, we analyze seismic waveforms recorded by a dense array on the Xishancun landside in Li County, Sichuan Province, southwest China during the Lunar New Year’s Eve (27 January 2017). A total of eight event clusters have been identified as a result of firework explosions. For each cluster, which comprises dozens of individual events with high similarity, we manually pick arrival times of the first event recorded by the array and locate it with a grid-search method. We then rotate three-component waveforms of all events from the east, north, and vertical coordinate system to the local LQT coordinates (L, positive direction perpendicular to the landslide surface and pointing downwards; Q, positive direction is from the launch location of firework to the station along the landslide surface; T, perpendicular to the plane formed by the L and Q directions, and the selected positive direction of the T axis makes LQT form the left-hand coordinate system), and stack the LQT components for those events with cross-correlation values CC ≥ 0.8 with respect to the first event. Characteristics of the stacked LQT components are also examined. The particle motions at each station are retrograde ellipse in the frequency range of ∼5–50 Hz, suggesting air-coupled Rayleigh waves generated by the firework explosions. Spectrograms of the Rayleigh waves also show clear dispersions, which might be used to image near-surface velocity structures. Although we cannot directly extract the phase velocities due to the limitation of the seismic array, our study shows that the fireworks might provide a low-cost and easy-to-use seismic source for imaging near-surface structures.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135569412","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}

引用次数: 0

Impact of the Uncertainty in the Parameters of the Earthquake Occurrence Model on Loss Estimates of Urban Building Portfolios 地震发生模型参数的不确定性对城市建筑组合损失估算的影响

3区地球科学

Seismological Research Letters Pub Date : 2023-10-20 DOI: 10.1785/0220230248

Alessandro Damiani, Valerio Poggi, Chiara Scaini, Mohsen Kohrangi, Paolo Bazzurro

{"title":"Impact of the Uncertainty in the Parameters of the Earthquake Occurrence Model on Loss Estimates of Urban Building Portfolios","authors":"Alessandro Damiani, Valerio Poggi, Chiara Scaini, Mohsen Kohrangi, Paolo Bazzurro","doi":"10.1785/0220230248","DOIUrl":"https://doi.org/10.1785/0220230248","url":null,"abstract":"Abstract Understanding the potential socioeconomic losses due to natural hazards, such as earthquakes, is of foremost importance in the field of catastrophe risk management. The construction of a probabilistic seismic risk model is complex and requires the tuning of several parameters essential to represent the seismic hazard of the region, the definition of the exposed inventory characteristics, and its vulnerability to ground motion. Because significant uncertainties could be associated with each model component, the loss estimates are often highly volatile. Nevertheless, to reduce the conceptual complexity and the computational burden, in many real-life applications these uncertainties are either not adequately treated or neglected altogether. The false high fidelity of the ensuing loss estimates can mislead decision-making strategies. Hence, it is useful to assess the influence that the variability in the estimated values of the model input parameters may exert on the final risk results and their relevant contributions. To this purpose, we have performed a sensitivity analysis of the results of an urban seismic risk assessment for Isfahan (Iran). Systematic variations have been applied to the values of the parameters that control the earthquake occurrence in the probabilistic seismic hazard model. Curves of input–output relative variations were built for different risk metrics with the goal of identifying the parameters most sensitive to input uncertainty. Our findings can be useful to support risk managers and practitioners in the process of building seismic hazard and risk models. We found that the Gutenberg–Richter a and b values, the maximum magnitude, and the threshold magnitude are large contributors to the variability of important risk measures, such as the 475 yr and the average annual loss, with the more frequent losses being, in general, most sensitive.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135569266","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}

引用次数: 0

Repeating Large Earthquakes along the Mexican Subduction Zone 沿墨西哥俯冲带重复的大地震

3区地球科学

Seismological Research Letters Pub Date : 2023-10-20 DOI: 10.1785/0220230243

Shri Krishna Singh, Raúl Daniel Corona-Fernandez, Miguel Ángel Santoyo, Arturo Iglesias

{"title":"Repeating Large Earthquakes along the Mexican Subduction Zone","authors":"Shri Krishna Singh, Raúl Daniel Corona-Fernandez, Miguel Ángel Santoyo, Arturo Iglesias","doi":"10.1785/0220230243","DOIUrl":"https://doi.org/10.1785/0220230243","url":null,"abstract":"Abstract Repeating large earthquakes (M ≥ 7), waveforms for which are nearly identical, have been identified only on the Mexican subduction thrust near Acapulco. These earthquakes occurred on 1962 (Ms 7.0) and 2021 (Ms 7.0, Mw 7.0). Here, we report on two more sequences of three repeating large earthquakes each in eastern and western Oaxaca, Mexico. The repeating earthquakes in eastern Oaxaca occurred on 23 March 1928 (Ms 7.5), 1965 (Ms 7.6, Mw 7.5), and 2020 (Ms 7.4, Mw 7.4), and in western Oaxaca on 4 August 1928 (Ms 7.4), 1968 (Ms 7.2, Mw 7.3), and 2018 (Ms 7.2, Mw 7.2). Galitzin seismograms of the earthquakes in each sequence at DeBilt, The Netherlands or at Strasbourg, France are strikingly similar for at least 2600 s after the P-wave arrival. Similarity of waveforms of earthquakes in each sequence and tests with seismograms of events locations for which are accurately known suggest that their source areas were less than 10–20 km of each other. Moment-rate functions of these events are remarkably simple. We also document quasi-repeating earthquakes in central Oaxaca on 17 June 1928 (Ms 7.6) and 29 November 1978 (Ms 7.6, Mw 7.6). Such events have similar locations with large overlap in primary slip but are not identical. Recently, Michoacán–Colima earthquakes of 1973 (Ms 7.5, Mw 7.6) and 2022 (Ms 7.6, Mw 7.6) were reported as quasi-repeaters. Repeating or quasi-repeating large earthquakes imply that they are known for all the other events in the sequence if we know the location and gross source parameters of one of them. This permits the estimation of recurrence periods and the delineation of seismic gaps with greater confidence. Repeating and quasi-repeating large earthquakes in Oaxaca, an unique observation, shed new light on seismic hazard of the region, provide further support for the characteristic earthquake model, and reveal remarkably persistent behavior of ruptures through multiple earthquake cycles.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135570122","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}

引用次数: 1

An Object Storage for Distributed Acoustic Sensing 分布式声传感的对象存储

3区地球科学

Seismological Research Letters Pub Date : 2023-10-20 DOI: 10.1785/0220230172

Yiyu Ni, Marine A. Denolle, Rob Fatland, Naomi Alterman, Bradley P. Lipovsky, Friedrich Knuth

引用次数: 0

The Pecos Array: A Temporary Nodal Seismic Experiment in the Pecos, Texas, Region of the Delaware Basin 佩科斯阵列:特拉华盆地德克萨斯州佩科斯地区的临时节点地震实验

3区地球科学

Seismological Research Letters Pub Date : 2023-10-19 DOI: 10.1785/0220230108

Jenna L. Faith, Marianne S. Karplus, Stephen A. Veitch, Diane I. Doser, Alexandros Savvaidis

{"title":"The Pecos Array: A Temporary Nodal Seismic Experiment in the Pecos, Texas, Region of the Delaware Basin","authors":"Jenna L. Faith, Marianne S. Karplus, Stephen A. Veitch, Diane I. Doser, Alexandros Savvaidis","doi":"10.1785/0220230108","DOIUrl":"https://doi.org/10.1785/0220230108","url":null,"abstract":"Abstract With increasing earthquakes in the Delaware basin since 2009, earthquake studies, including accurate hypocenters, are critically needed in the Delaware basin to identify the structures producing earthquakes, and to determine if they are related to unconventional petroleum development and production. In 2018, with funding from the Texas Seismological Network, we deployed and maintained a nodal network of 25 Magseis Fairfield Z-Land Generation 2 5-Hz seismic nodes in the Pecos, Texas, region of the Delaware basin, known as, The Pecos Array. The network was deployed from November 2018 to the beginning of January 2020, with an additional two months of data recorded in September and October 2020. The network collected continuous three-component data with a 1000-Hz sampling rate. The spacing of the nodes varied from ∼2 km in town to ∼10 km farther away from the city center. The primary goal of this network was to improve estimation of event hypocenters, which will help to determine why there has been an increase in earthquakes over the past several years. In this article, we summarize the scientific motivation, deployment details, and data quality of this network. Data quality statistics show that we successfully collected continuous data with signal-to-noise ratios that allow us to detect and locate events, hundreds of them being estimated at ML&lt;0.50. This unique dataset is contributing to new seismotectonic studies in the Delaware basin.","PeriodicalId":21687,"journal":{"name":"Seismological Research Letters","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135778811","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}

引用次数: 0