Earthquake Science最新文献

{"title":"Structural similarity of lithospheric velocity models of Chinese mainland","authors":"Feng Huang ,&nbsp;Xueyang Bao ,&nbsp;Qili Andy Dai ,&nbsp;Xinfu Li","doi":"10.1016/j.eqs.2024.05.004","DOIUrl":"10.1016/j.eqs.2024.05.004","url":null,"abstract":"<div><div>Existing lithospheric velocity models exhibit similar structures typically associated with the first-order tectonic features, with dissimilarities due to different data and methods used in model generation. The quantification of model structural similarity can help in interpreting the geophysical properties of Earth’s interior and establishing unified models crucial in natural hazard assessment and resource exploration. Here we employ the complex wavelet structural similarity index measure (CW-SSIM) active in computer image processing to analyze the structural similarity of four lithospheric velocity models of Chinese mainland published in the past decade. We take advantage of this method in its multiscale definition and insensitivity to slight geometrical distortion like translation and scaling, which is particularly crucial in the structural similarity analysis of velocity models accounting for uncertainty and resolution. Our results show that the CW-SSIM values vary in different model pairs, horizontal locations, and depths. While variations in the inter-model CW-SSIM are partly owing to different databases in the model generation, the difference of tomography methods may significantly impact the similar structural features of models, such as the low similarities between the full-wave based FWEA18 and other three models in northeastern China. We finally suggest potential solutions for the next generation of tomographic modeling in different areas according to corresponding structural similarities of existing models.</div></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"37 6","pages":"Pages 514-528"},"PeriodicalIF":1.2,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322416","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":"An illustrated guide to: Parsimonious multi-scale full-waveform inversion","authors":"Andreas Fichtner,&nbsp;Solvi Thrastarson,&nbsp;Dirk-Philip van Herwaarden,&nbsp;Sebastian Noe","doi":"10.1016/j.eqs.2024.07.004","DOIUrl":"10.1016/j.eqs.2024.07.004","url":null,"abstract":"<div><div>Having been a seemingly unreachable ideal for decades, 3-D full-waveform inversion applied to massive seismic datasets has become reality in recent years. Often achieving unprecedented resolution, it has provided new insight into the structure of the Earth, from the upper few metres of soil to the entire globe. Motivated by these successes, the technology is now being translated to medical ultrasound and non-destructive testing. Despite remarkable progress, the computational cost of full-waveform inversion continues to be a major concern. It limits the amount of data that can be exploited, and it largely inhibits quantitative and comprehensive uncertainty analyses. These notes complement a presentation on recent developments in full-waveform inversion that are intended to reduce computational cost and assimilate more data, thereby improving tomographic resolution. The suite of strategies includes flexible and user-friendly spectral-element simulations, the design of wavefield-adapted meshes that harness prior information on wavefield geometry, dynamic mini-batch optimisation that naturally takes advantage of data redundancies, and collaborative multi-scale updating to jointly constrain crustal and mantle structure.</div></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"37 6","pages":"Pages 574-583"},"PeriodicalIF":1.2,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322420","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":"Evaluation of crustal deformation and associated strong motions induced by the 2022 Paktika earthquake, Afghanistan","authors":"A. Bari Jahed ,&nbsp;Ömer Aydan ,&nbsp;Takashi Ito ,&nbsp;Naoki Iwata","doi":"10.1016/j.eqs.2024.07.001","DOIUrl":"10.1016/j.eqs.2024.07.001","url":null,"abstract":"<div><div>The 2022 Paktika earthquake (moment magnitude: 6.2) occurred on June 22, 2022, near the border between the Khost and Paktika Provinces of Afghanistan, causing heavy damage and casualties in Paktika Province. This study evaluated the crustal deformation and associated strong motions induced by the Paktika earthquake. Crustal deformations were determined using the Differential Interferometric Synthetic Aperture Radar (DInSAR) technique and three-dimensional finite element method (3D-FEM) and the results were compared. The permanent ground displacements obtained from the DInSAR and 3D-FEM analyses were similar in terms of amplitude and areal distribution. Strong motions were estimated using the 3D-FEM with and without considering regional topography. The estimations of maximum ground acceleration, velocity, and permanent ground deformations were compared among each other as well as with those inferred from failures of some simple structures in the Spera and Gayan districts. The inferred maximum ground acceleration and velocity from the failed adobe structures were more than 300 Gal and 50 cm/s, respectively, nearly consistent with the estimates obtained using empirical methods. The empirical method yielded a maximum ground acceleration of 347 Gal, whereas the maximum ground velocity was approximately 50 cm/s. In light of these findings, some surface expressions of crustal deformations and strong ground motions, such as failures of soil and rock slopes and rockfalls, have been presented. The rock slope failures in the epicentral area were consistent with those observed during various earthquakes in Afghanistan and worldwide.</div></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"37 6","pages":"Pages 546-557"},"PeriodicalIF":1.2,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322418","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":"Seismogenic model of the 2023 MW5.5 Pingyuan earthquake in North China Plain and its tectonic implications","authors":"Shiguang Wang ,&nbsp;Libo Han ,&nbsp;Junju Xie ,&nbsp;Liping Fan ,&nbsp;Xiang Huang ,&nbsp;Jinmeng Bi ,&nbsp;Hongfeng Yang ,&nbsp;Lihua Fang","doi":"10.1016/j.eqs.2024.06.008","DOIUrl":"10.1016/j.eqs.2024.06.008","url":null,"abstract":"<div><div>The 6 August 2023 <em>M</em>_W5.5 Pingyuan earthquake is the largest earthquake in the central North China Plain (NCP) over the past two decades. Due to the thick sedimentary cover, no corresponding active faults have been reported yet in the epicenter area. Thus, this earthquake presents a unique opportunity to delve into the buried active faults beneath the NCP. By integrating strong ground motion records, high-precision aftershock sequence relocation, and focal mechanism solutions, we gain insights into the seismotectonics of the Pingyuan earthquake. The aftershocks are clustered at depths ranging from 15 to 20 km and delineate a NE-SW trend, consistent with the distribution of ground motion records. A NE-SW nodal plane (226°) of the focal mechanism solutions is also derived from regional waveform inversion, suggesting that the mainshock was dominated by strike-slip motion with minor normal faulting component. Integrating regional geological data, we propose that an unrecognized fault between the NE-SW trending Gaotang and Lingxian-Yangxin faults is the seismogenic fault of this event. Based on the S-wave velocity structure beneath the NCP, this fault probably extends into the lower crust with a high angle. Considering the tectonic regime and stress state, we speculate that the interplay of shear strain between the Amurian and South China blocks and the hot upwelling magma from the subducted paleo Pacific flat slab significantly contributed to the generation of the Pingyuan earthquake.</div></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"37 6","pages":"Pages 499-513"},"PeriodicalIF":1.2,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322542","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":"Assessing the effects of model parameter assumptions on surface-wave inversion results","authors":"Xuezhen Zhang ,&nbsp;Xiaodong Song","doi":"10.1016/j.eqs.2024.07.002","DOIUrl":"10.1016/j.eqs.2024.07.002","url":null,"abstract":"<div><div>Surface-wave inversion is a powerful tool for revealing the Earth’s internal structure. However, aside from shear-wave velocity (<em>v</em>_S), other parameters can influence the inversion outcomes, yet these have not been systematically discussed. This study investigates the influence of various parameter assumptions on the results of surface-wave inversion, including the compressional and shear velocity ratio (<em>v</em>_P/<em>v</em>_S), shear-wave attenuation (<em>Q</em>_S), density (<em>ρ</em>), Moho interface, and sedimentary layer. We constructed synthetic models to generate dispersion data and compared the obtained results with different parameter assumptions with those of the true model. The results indicate that the <em>v</em>_P/<em>v</em>_S ratio, <em>Q</em>_S, and density (<em>ρ</em>) have minimal effects on absolute velocity values and perturbation patterns in the inversion. Conversely, assumptions about the Moho interface and sedimentary layer significantly influenced absolute velocity values and perturbation patterns. Introducing an erroneous Moho-interface depth in the initial model of the inversion significantly affected the <em>v</em>_S model near that depth, while using a smooth initial model results in relatively minor deviations. The assumption on the sedimentary layer not only affects shallow structure results but also impacts the result at greater depths. Non-linear inversion methods outperform linear inversion methods, particularly for the assumptions of the Moho interface and sedimentary layer. Joint inversion with other data types, such as receiver functions or Rayleigh wave ellipticity, and using data from a broader period range or higher-mode surface waves, can mitigate these deviations. Furthermore, incorporating more accurate prior information can improve inversion results.</div></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"37 6","pages":"Pages 529-545"},"PeriodicalIF":1.2,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322417","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":"An open access dataset for strong-motion data (PGA, PGV, and Site VS) of 2023 M6.2 Jishishan, Gansu, China earthquake","authors":"Jian Zhou ,&nbsp;Li Li ,&nbsp;Nan Xi ,&nbsp;Kun Chen ,&nbsp;Xin Tian ,&nbsp;Chao Wang ,&nbsp;Jifeng Tian","doi":"10.1016/j.eqs.2024.04.002","DOIUrl":"10.1016/j.eqs.2024.04.002","url":null,"abstract":"","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"37 6","pages":"Pages 584-587"},"PeriodicalIF":1.2,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322421","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":"Mechanisms to explain soil liquefaction triggering, development, and persistence during an earthquake","authors":"Fernando Teixeira","doi":"10.1016/j.eqs.2024.07.003","DOIUrl":"10.1016/j.eqs.2024.07.003","url":null,"abstract":"<div><div>Mechanisms have been proposed to explain the triggering, development, and persistence of soil liquefaction. The mechanism explaining the horizontal failure plane (triggering) and its depth below the phreatic surface is governed by the flux properties and effective stress at that plane. At the failure plane, the pore water pressure was higher than the effective stress, and the volume change was the highest. The pore water pressure is a function of the soil profile features (particularly the phreatic zone width) and bedrock motion (horizontal acceleration). The volume change at the failure plane is a function of the intrinsic permeability of the soil and bedrock displacement. The failure plane was predicted to occur during the oscillation with the highest amplitude, disregarding further bedrock motion, which was consistent with low seismic energy densities. Two mechanisms were proposed to explain the persistence of soil liquefaction. The first is the existence of low-permeability layers in the depth range in which the failure planes are predicted to occur. The other allows for the persistence and development of soil liquefaction; it is consistent with homogeneous soils and requires water inflow from bedrock water springs. The latter explains many of the features of soil liquefaction observed during earthquakes, namely, surficial effects, “instant” liquefaction, and the occurrence of short- and long-term changes in the level of the phreatic surfaces. This model (hypothesis), the relationship between the flux characteristics and loss of soil shear strength, provides self-consistent constraints on the depth below the phreatic surfaces where the failure planes are observed (expected to occur). It requires further experimental and observational evidence. Similar reasoning can be used to explain other saturated soil phenomena.</div></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"37 6","pages":"Pages 558-573"},"PeriodicalIF":1.2,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322419","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":"Assessment of earthquake location uncertainties for the design of local seismic networks","authors":"Antonio Fuggi ,&nbsp;Simone Re ,&nbsp;Giorgio Tango ,&nbsp;Sergio Del Gaudio ,&nbsp;Alessandro Brovelli ,&nbsp;Giorgio Cassiani","doi":"10.1016/j.eqs.2024.06.006","DOIUrl":"10.1016/j.eqs.2024.06.006","url":null,"abstract":"<div><p>The ability to estimate earthquake source locations, along with the appraisal of relevant uncertainties, is paramount in monitoring both natural and human-induced micro-seismicity. For this purpose, a monitoring network must be designed to minimize the location errors introduced by geometrically unbalanced networks. In this study, we first review different sources of errors relevant to the localization of seismic events, how they propagate through localization algorithms, and their impact on outcomes. We then propose a quantitative method, based on a Monte Carlo approach, to estimate the uncertainty in earthquake locations that is suited to the design, optimization, and assessment of the performance of a local seismic monitoring network. To illustrate the performance of the proposed approach, we analyzed the distribution of the localization uncertainties and their related dispersion for a highly dense grid of theoretical hypocenters in both the horizontal and vertical directions using an actual monitoring network layout. The results expand, quantitatively, the qualitative indications derived from purely geometrical parameters (azimuthal gap (AG)) and classical detectability maps. The proposed method enables the systematic design, optimization, and evaluation of local seismic monitoring networks, enhancing monitoring accuracy in areas proximal to hydrocarbon production, geothermal fields, underground natural gas storage, and other subsurface activities. This approach aids in the accurate estimation of earthquake source locations and their associated uncertainties, which are crucial for assessing and mitigating seismic risks, thereby enabling the implementation of proactive measures to minimize potential hazards. From an operational perspective, reliably estimating location accuracy is crucial for evaluating the position of seismogenic sources and assessing possible links between well activities and the onset of seismicity.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"37 5","pages":"Pages 415-433"},"PeriodicalIF":1.2,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1674451924000661/pdfft?md5=fdf5e5b23a50a9c78a7e5af61bce7542&pid=1-s2.0-S1674451924000661-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993508","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":"Science and reflections: With some thoughts to young applied scientists and engineers","authors":"Robert L. Nowack","doi":"10.1016/j.eqs.2024.06.004","DOIUrl":"10.1016/j.eqs.2024.06.004","url":null,"abstract":"<div><p>I provide some science and reflections from my experiences working in geophysics, along with connections to computational and data sciences, including recent developments in machine learning. I highlight several individuals and groups who have influenced me, both through direct collaborations as well as from ideas and insights that I have learned from. While my reflections are rooted in geophysics, they should also be relevant to other computational scientific and engineering fields. I also provide some thoughts for young, applied scientists and engineers.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"37 5","pages":"Pages 459-493"},"PeriodicalIF":1.2,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1674451924000648/pdfft?md5=aa12c644eeb75b5e31e4175a03b05aaa&pid=1-s2.0-S1674451924000648-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993511","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":"Critical analysis of the ULF power depression as a possible Tohoku earthquake precursor","authors":"Vyacheslav A. Pilipenko ,&nbsp;Valery A. Martines-Bedenko ,&nbsp;Akimasa Yoshikawa ,&nbsp;Kirolosse M. Girgis","doi":"10.1016/j.eqs.2024.06.003","DOIUrl":"10.1016/j.eqs.2024.06.003","url":null,"abstract":"<div><p>Among electromagnetic methods of short-term earthquake prediction, an approach is being actively developed based on the phenomenon of magnetic ultra-low-frequency (ULF) power depression occurring a few days before an earthquake. In particular, a nighttime geomagnetic power depression in the band 0.03–0.05 Hz was observed approximately 5 days before the catastrophic Tohoku 2011 earthquake. To verify the reliability of this method, we performed an extended analysis using data from magnetometer arrays JMA, MAGDAS, PWING, and INTERMAGNET. The selected stations included sites close to the epicenter (&lt;300 km) and remote points (∼10000 km). The band-integrated spectral power of nighttime magnetic noise decreased significantly from March 6–9, several days before the earthquake. However, such variations occur simultaneously not only at nearby stations but also at distant stations. During this event, the ULF power depression was caused by low global geomagnetic activity, as evidenced by the planetary index SME. Thus, the depression of geomagnetic ULF noise cannot be considered a reliable short-term precursor.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"37 5","pages":"Pages 407-414"},"PeriodicalIF":1.2,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1674451924000636/pdfft?md5=e661963ec366dc9bd3268ca73c472ff4&pid=1-s2.0-S1674451924000636-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141992819","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}