Studia Geophysica et Geodaetica最新文献_第7页

Rate of seismic deformation in the Gulf of Aqaba inferred from moment-tensor summation 由矩张量求和推断的亚喀巴湾地震变形速率

IF 0.9 4区地球科学

Studia Geophysica et Geodaetica Pub Date : 2020-11-09 DOI: 10.1007/s11200-020-1028-7

Sattam Almadani

{"title":"Rate of seismic deformation in the Gulf of Aqaba inferred from moment-tensor summation","authors":"Sattam Almadani","doi":"10.1007/s11200-020-1028-7","DOIUrl":"https://doi.org/10.1007/s11200-020-1028-7","url":null,"abstract":"This study aims to quantify the rate of coseismic deformation in the Gulf of Aqaba. Earthquake catalogue, Gutenberg-Richter relationship and fault plane solutions were integrated to measure the size and shape of deformation using the moment-tensor summation technique. First, the Gutenberg-Richter relationship was established using seismicity data from the period of 1964–2019. Then, the moment-tensor summation based on 44 focal mechanism solutions was used to calculate the shape of deformation. The eigenvalues of moment-tensor reflect the diversity of focal mechanism solutions that alternate from normal to strike-slip fault styles in the deformation zone. The analysis reveals a dominant shear deformation in the Gulf of Aqaba that extends in a direction of N42.2°E at a rate of 2.6 ± 0.04 mm yr?1and shortens in the direction of N305.2°E at a rate of 2.0 ± 0.02 mm yr?1. These results suggest that the active deformation occurring in the Gulf of Aqaba is due to the relative tectonic movements between the Arabian and African plates, as well as Sinai subplate.","PeriodicalId":22001,"journal":{"name":"Studia Geophysica et Geodaetica","volume":"64 4","pages":"504 - 519"},"PeriodicalIF":0.9,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11200-020-1028-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4399623","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}

引用次数: 1

Exact line search method for using the L1-norm misfit function in full waveform inversion 利用l1范数失拟函数进行全波形反演的精确线搜索方法

IF 0.9 4区地球科学

Studia Geophysica et Geodaetica Pub Date : 2020-11-09 DOI: 10.1007/s11200-020-0904-5

Xiaona Ma, Guanghe Liang, Shanhui Xu, Zhiyuan Li, Haixin Feng

{"title":"Exact line search method for using the L1-norm misfit function in full waveform inversion","authors":"Xiaona Ma, Guanghe Liang, Shanhui Xu, Zhiyuan Li, Haixin Feng","doi":"10.1007/s11200-020-0904-5","DOIUrl":"https://doi.org/10.1007/s11200-020-0904-5","url":null,"abstract":"Full waveform inversion (FWI) is a non-linear inverse problem that can be sensitive to noise. The tolerance of the noise-interference characteristics depends on the types of misfit functions. To date, different misfit functions, such as the least-squares norm (L2), the least-absolute-value norm (L1), and combinations of the two (e.g., the Huber and hybrid criteria), have been applied to FWI. The L2 norm is highly sensitive to non-Gaussian errors in the data and gives rise to high-amplitude artifacts in reconstructed models. For non-Gaussian noise data, the L1 norm and the Huber and hybrid criteria always reliably reconstruct models. However, the Huber and hybrid criteria require tedious error investigations to estimate their threshold criterion. Thus, the L1 norm is adopted here to improve the anti-noise ability of the FWI. The step length is closely related to the misfit function, and an optimal step-length estimation method can rapidly make the FWI algorithm reach the global minimum, with a reduced number of iterations and fewer extra forward modeling simulations during each iteration. The step length can usually be obtained using the exact or inexact line search method. Generally, the exact line search method is faster than the inexact one. Therefore, we derived an exact line search method for the L1 norm in the FWI process. Its effectiveness was tested using noise-free data from Overthrust and the SEG/EAGE salt models. The results demonstrate that this method can recover high-resolution velocity models with low computational costs. Numerical tests using the synthetic Overthrust model contaminated by strong noise were used to further validate the robustness of this exact line search method.","PeriodicalId":22001,"journal":{"name":"Studia Geophysica et Geodaetica","volume":"64 4","pages":"483 - 503"},"PeriodicalIF":0.9,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11200-020-0904-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4399628","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}

引用次数: 1

Effect of a high-resolution global crustal model on gravimetric geoid determination: a case study in a mountainous region 高分辨率全球地壳模型对重力大地水准面确定的影响:以山区为例

IF 0.9 4区地球科学

Studia Geophysica et Geodaetica Pub Date : 2020-10-27 DOI: 10.1007/s11200-020-1023-z

Ramazan Alpay Abbak

引用次数: 6

Modeling 3D acoustic-wave propagation using modified cuboid-based staggered-grid finite-difference methods with temporal and spatial high-order accuracy 基于改进长方体交错网格的时空高阶精度有限差分方法模拟三维声波传播

IF 0.9 4区地球科学

Studia Geophysica et Geodaetica Pub Date : 2020-10-27 DOI: 10.1007/s11200-020-1013-1

Shigang Xu, Yang Liu

引用次数: 0

Gravity sparse inversion using the interior-point method and a general model weighting function 利用内点法和一般模型加权函数进行重力稀疏反演

IF 0.9 4区地球科学

Studia Geophysica et Geodaetica Pub Date : 2020-10-24 DOI: 10.1007/s11200-020-0831-5

Wenwu Zhu, Junhuan Peng, Sanming Luo, Xiangang Meng, Jinzhao Liu, Chuandong Zhu

{"title":"Gravity sparse inversion using the interior-point method and a general model weighting function","authors":"Wenwu Zhu, Junhuan Peng, Sanming Luo, Xiangang Meng, Jinzhao Liu, Chuandong Zhu","doi":"10.1007/s11200-020-0831-5","DOIUrl":"https://doi.org/10.1007/s11200-020-0831-5","url":null,"abstract":"This study presents an optimized gravity-sparse inversion method. The proposed method minimizes the global objective function using interior-point method for boundary constraints and a general weighting function comprising the depth, compactness, and kernel weighting functions of the density models. For the compactness weighting function, practical experiments demonstrate that the recovered model becomes more compact with an increasing value for the relative exponential factor β. However, if no appropriate boundary-constraint method is applied, the inversion results cannot be controlled within the designated constraint bounds when β needs to be set to a large value to obtain compact inversion results. The interior-point method allows the use of a larger β to obtain more compact inversion results without violating the boundary constraints. Additionally, models in close proximity can more clearly be recognized using this method. To improve the computational efficiency and obtain a more accurate regularization parameter, the preconditioned conjugate gradient and L-curve, or line search methods, were also applied. The proposed method was applied for three synthetic examples: two positive bodies adjacent to each other at different depths inverted using noise-free gravity anomaly data, three bodies (positive or negative) at different depths inverted using noise-free or contaminated gravity anomaly data, and three bodies (positive or negative) characterized by a certain dip angle inverted using contaminated gravity anomaly data. This method was also applied for the inversion of a Woodlawn sulfide body, Missouri iron ore body, and granitoid rock body in the Rio Maria region in the state of Para, Brazil. In all six test cases, larger β values were used and the density models were recovered with sharper boundaries within the designated bounds.","PeriodicalId":22001,"journal":{"name":"Studia Geophysica et Geodaetica","volume":"64 4","pages":"419 - 435"},"PeriodicalIF":0.9,"publicationDate":"2020-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11200-020-0831-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4950540","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}

引用次数: 1

Stable optimization of finite-difference operators for seismic wave modeling 地震波模拟有限差分算子的稳定优化

IF 0.9 4区地球科学

Studia Geophysica et Geodaetica Pub Date : 2020-09-03 DOI: 10.1007/s11200-019-0487-1

Jian Wang, Liu Hong

引用次数: 2

A stable regularization method of downward continuation of potential field 位场向下延拓的稳定正则化方法

IF 0.9 4区地球科学

Studia Geophysica et Geodaetica Pub Date : 2020-07-27 DOI: 10.1007/s11200-019-0760-3

Jinpeng Li, Yingtang Zhang, Hongbo Fan, Zhining Li, Fucheng Sun

{"title":"A stable regularization method of downward continuation of potential field","authors":"Jinpeng Li, Yingtang Zhang, Hongbo Fan, Zhining Li, Fucheng Sun","doi":"10.1007/s11200-019-0760-3","DOIUrl":"https://doi.org/10.1007/s11200-019-0760-3","url":null,"abstract":"Downward continuation is known as one of the crucial steps in interpreting gravity or magnetic data. As the continuation depth and the influence of noise increases, the results of downward continuation become unstable. Based on the computation of the Chebyshev-Padé approximation function obtained by the Tikhonov regularization, this paper proposes a new regularized method intended for the downward continuation of potential fields. The Chebyshev-Padé approximation function is applied to calculate the continuation factor. In this study, the cross-correlation method is adopted to calculate the cut-off wavenumber, while the regularized low-pass filter is designed to calculate the downward continuation of the potential field. In order to validate this method, numerical simulation is conducted. We calculate the root mean square error of the theoretical data on the target plane and the data of downward continuation, as obtained using the improved regularization operator method, the Chebyshev-Padé approximation function method, the regularized Chebyshev-Padé approximation function method, and the method proposed in this paper, based on which a comparison is conducted. According to the simulation and experimental results, the effects of the continuation depth can be reduced significantly by the proposed method. Besides, the method demonstrates strong resistance to noise.","PeriodicalId":22001,"journal":{"name":"Studia Geophysica et Geodaetica","volume":"64 3","pages":"391 - 406"},"PeriodicalIF":0.9,"publicationDate":"2020-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11200-019-0760-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5041928","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}

引用次数: 1

Desert seismic data denoising based on energy spectrum analysis in empirical curvelet domain 基于经验曲线域能谱分析的沙漠地震数据去噪

IF 0.9 4区地球科学

Studia Geophysica et Geodaetica Pub Date : 2020-07-18 DOI: 10.1007/s11200-019-0476-4

Mo Li, Yue Li, Ning Wu, Yanan Tian

{"title":"Desert seismic data denoising based on energy spectrum analysis in empirical curvelet domain","authors":"Mo Li, Yue Li, Ning Wu, Yanan Tian","doi":"10.1007/s11200-019-0476-4","DOIUrl":"https://doi.org/10.1007/s11200-019-0476-4","url":null,"abstract":"Desert seismic events are disturbed and contaminated by strong random noise, which complicates the subsequent processing, inversion, and interpretation of the data. Thus, noise suppression is an important task. The complex characteristics of random noise in desert seismic records differ completely from those of Gaussian white noise such that they are non-stationary, non-Gaussian, non-linear and low frequency. In addition, desert seismic signals and strong random noise generally share the same frequency bands. Such factors bring great difficulties in the processing and interpretation of desert seismic data. To obtain high-quality data in desert seismic exploration, we have developed an effective denoising method for desert seismic data, which performs energy spectrum analysis in the empirical curvelet transform (ECT) domain. The empirical curvelet coefficients are divided into two different groups according to their energy spectrum distributions. In the first group, which contains fewer effective signals, a large threshold is selected to remove lots of random noise; the second group, with more effective signals, a coherence-enhancing diffusion filter (CEDF) is used to eliminate the noise. Unlike traditional curvelet transforms, ECT not only has the multi-scale, multi-direction, and anisotropy properties of conventional curvelet transform, but also provides adaptability to separate the effective signals from the random noise. We examine synthetic and field desert seismic data. The denoising results demonstrate that the proposed method can be used for preserving effective signals and removing random noise.","PeriodicalId":22001,"journal":{"name":"Studia Geophysica et Geodaetica","volume":"64 3","pages":"373 - 390"},"PeriodicalIF":0.9,"publicationDate":"2020-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11200-019-0476-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4722084","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}

引用次数: 4

Improving the accuracy of the expanded anisotropic eikonal equation at larger offsets using Levin T-transformation 利用Levin t变换提高大偏移量下扩展各向异性斜向方程的精度

IF 0.9 4区地球科学

Studia Geophysica et Geodaetica Pub Date : 2020-07-15 DOI: 10.1007/s11200-020-0610-3

Humbang Purba, Awali Priyono, Wahyu Triyoso, Mochamad Apri

{"title":"Improving the accuracy of the expanded anisotropic eikonal equation at larger offsets using Levin T-transformation","authors":"Humbang Purba, Awali Priyono, Wahyu Triyoso, Mochamad Apri","doi":"10.1007/s11200-020-0610-3","DOIUrl":"https://doi.org/10.1007/s11200-020-0610-3","url":null,"abstract":"In an anisotropic model, traveltime can be determined approximately by numerical solution of the eikonal equation in terms of an anellipticity parameter η, using perturbation theory. However, its accuracy decreases under the effect of strong anisotropy at larger offsets. It becomes invalid for determining normal moveout velocity and anellipticity parameter in seismic processing. We propose a new approach using Levin T-transformation to transform the expanded traveltime in the transversely isotropic medium with vertical axis of symmetry (VTI) into rational form. The objective of this study is to provide a new traveltime approximation that is more accurate at larger offsets. In this study, we derive Levin algorithm and determine the optimal value of Levin parameters, which is a key step in achieving better accuracy. In a numerical experiment, we compare the accuracy between Levin T-transformation and second sequence of Shanks transformation in a homogeneous VTI medium. We also implement both approximations in a velocity analysis and stacking traces using synthetic common midpoint gathers on a multilayer earth model. The proposed method shows a superiority in accuracy to existing methods over a range of offsets with offset-to-depth ratio up to 6 and anellipticity parameter 0–0.5.","PeriodicalId":22001,"journal":{"name":"Studia Geophysica et Geodaetica","volume":"64 3","pages":"349 - 372"},"PeriodicalIF":0.9,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11200-020-0610-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4608814","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}

引用次数: 1

Impact of environmental phenomena on continuous relative gravity measurements performed in urban area 环境现象对城市地区连续相对重力测量的影响

IF 0.9 4区地球科学

Studia Geophysica et Geodaetica Pub Date : 2020-06-22 DOI: 10.1007/s11200-021-0536-4

Branislav Hábel, Juraj Janák, Juraj Papčo, Miloš Val’ko

{"title":"Impact of environmental phenomena on continuous relative gravity measurements performed in urban area","authors":"Branislav Hábel, Juraj Janák, Juraj Papčo, Miloš Val’ko","doi":"10.1007/s11200-021-0536-4","DOIUrl":"https://doi.org/10.1007/s11200-021-0536-4","url":null,"abstract":"The relative monitoring gravimeter gPhoneX #108 was installed in the building of Faculty of Civil Engineering of the Slovak University of Technology in Bratislava in the beginning of 2016. Main purpose of the paper is to analyze how external environmental phenomena generating non-gravitational signal, such as strong human activity, ambient noise and tilting of observing site due to solar radiation, can influence the quality of relative gravity measurements and their suitability for geodynamic applications. For this purpose, we accomplished spectral analysis of gravity data with different sampling rate, examination of instrumental drift, and tidal analysis of hourly gravity records. Our study showed that the gPhoneX #108 gravity measurements are adversely affected by the tilting of the building, where the gravimeter is located. This effect produces a significant non gravitational signal with characteristic daily and seasonal variation depending on the weather conditions. The instability of the observing site also generates a strong non-gravitational signal and corrupts the estimation of tidal parameters mainly in a diurnal tidal band. The investigation of the instrumental drift proved its irregular character due to the changes of temperature in the operating room. Another limitation factor for detection of small gravity changes is the level of ambient noise with the average daily amplitude of about 100 nm s?2. Obtained experimental results can be useful for planning and performing the relative gravity measurements in a noisy environment, or in the case of an instable observing site. The most significant non-gravitational signal with variable daily and seasonal influence was caused by the instability of the observing site. In order to minimize this influence we recommend regular calibration of the built-in tiltmeters.","PeriodicalId":22001,"journal":{"name":"Studia Geophysica et Geodaetica","volume":"64 3","pages":"330 - 348"},"PeriodicalIF":0.9,"publicationDate":"2020-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11200-021-0536-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5164728","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}

引用次数: 2