arXiv - PHYS - Geophysics最新文献_第4页

Gaussian Processes enabled model calibration in the context of deep geological disposal 高斯过程在深层地质弃置中实现了模型校准

arXiv - PHYS - Geophysics Pub Date : 2024-09-04 DOI: arxiv-2409.02576

Lennart Paul, Jorge-Humberto Urrea-Quintero, Umer Fiaz, Ali Hussein, Hazem Yaghi, Henning Wessels, Ulrich Römer, Joachim Stahlmann

引用次数: 0

A two-way coupled high resolution wave hindcast for the South China Sea 南海双向耦合高分辨率波浪后报

arXiv - PHYS - Geophysics Pub Date : 2024-09-04 DOI: arxiv-2409.02472

Tiziano Bagnasco, Alessandro Stocchino, Michalis I. Vousdoukas, Jinghua Wang

{"title":"A two-way coupled high resolution wave hindcast for the South China Sea","authors":"Tiziano Bagnasco, Alessandro Stocchino, Michalis I. Vousdoukas, Jinghua Wang","doi":"arxiv-2409.02472","DOIUrl":"https://doi.org/arxiv-2409.02472","url":null,"abstract":"In the present study, we performed a 53-year wave hindcast (1970-2022) for a\u0000significant portion of the South China Sea (SCS) with an unstructured mesh that\u0000reaches considerably high resolution along the coasts of the Guangdong province\u0000(China). The adopted modeling approach is based on the fully two-way coupled\u0000SCHISM-WWMIII numerical suite. The model was forced with ERA5 wind velocities\u0000that were compared to IFREMER altimeter wind velocities and then bias-corrected\u0000for a more accurate treatment of the wind component. Eight major tidal\u0000harmonics extracted from FES2014 were imposed to the open boundaries. After a\u0000preliminary mesh independence analysis, the model results have been validated\u0000against satellite altimeter observations retrieved from the European Space\u0000Agency database spanning the period from 1992 to 2019. Moreover, 28 year\u0000in-situ measurements from two coastal wave buoys and data from four tidal gauge\u0000stations (approximately 20 years) were used to test the nearshore skills of the\u0000model. Several statistical indicators have been used to evaluate the offshore\u0000and nearshore performance of the model results in terms of the main wave\u0000parameters (significant wave height, peak wave period, mean wave direction) and\u0000water levels. All statistical metrics suggest that the present hindcast\u0000improved the predictions of waves and water levels compared to previous\u0000datasets, especially in the coastal regions. The high spatial resolution\u0000together with a full coupling allowed the model to capture and simulate\u0000processes that are induced by the non-linear interactions between waves and\u0000currents, especially nearshore.","PeriodicalId":501270,"journal":{"name":"arXiv - PHYS - Geophysics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Attenuation of marine seismic interference noise employing a customized U-Net 利用定制 U-Net 减小海洋地震干扰噪音

arXiv - PHYS - Geophysics Pub Date : 2024-09-03 DOI: arxiv-2409.01673

Jing Sun, Sigmund Slang, Thomas Elboth, Thomas Larsen Greiner, Steven McDonald, Leiv-J Gelius

{"title":"Attenuation of marine seismic interference noise employing a customized U-Net","authors":"Jing Sun, Sigmund Slang, Thomas Elboth, Thomas Larsen Greiner, Steven McDonald, Leiv-J Gelius","doi":"arxiv-2409.01673","DOIUrl":"https://doi.org/arxiv-2409.01673","url":null,"abstract":"Marine seismic interference noise occurs when energy from nearby marine\u0000seismic source vessels is recorded during a seismic survey. Such noise tends to\u0000be well preserved over large distances and cause coherent artifacts in the\u0000recorded data. Over the years, the industry has developed various denoising\u0000techniques for seismic interference removal, but although well performing they\u0000are still time-consuming in use. Machine-learning based processing represents\u0000an alternative approach, which may significantly improve the computational\u0000efficiency. In case of conventional images, autoencoders are frequently\u0000employed for denoising purposes. However, due to the special characteristics of\u0000seismic data as well as the noise, autoencoders failed in the case of marine\u0000seismic interference noise. We therefore propose the use of a customized U-Net\u0000design with element-wise summation as part of the skip-connection blocks to\u0000handle the vanishing gradient problem and to ensure information fusion between\u0000high- and low-level features. To secure a realistic study, only seismic field\u0000data were employed, including 25000 training examples. The customized U-Net was\u0000found to perform well leaving only minor residuals, except for the case when\u0000seismic interference noise comes from the side. We further demonstrate that\u0000such noise can be treated by slightly increasing the depth of our network.\u0000Although our customized U-Net does not outperform a standard commercial\u0000algorithm in quality, it can (after proper training) read and process one\u0000single shot gather in approximately 0.02s. This is significantly faster than\u0000any existing industry denoising algorithm. In addition, the proposed network\u0000processes shot gathers in a sequential order, which is an advantage compared\u0000with industry algorithms that typically require a multi-shot input to break the\u0000coherency of the noise.","PeriodicalId":501270,"journal":{"name":"arXiv - PHYS - Geophysics","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multi-block chemometric approaches to the unsupervised spectral classification of geological samples 地质样本无监督光谱分类的多块化学计量学方法

arXiv - PHYS - Geophysics Pub Date : 2024-09-03 DOI: arxiv-2409.04466

Beatriz Galindo-Prieto, Ian S. Mudway, Johan Linderholm, Paul Geladi

引用次数: 0

Joining simplified physics models with coarse grids to speed-up intractable 3D time-domain simulations 将简化物理模型与粗网格结合起来，加快棘手的三维时域模拟速度

arXiv - PHYS - Geophysics Pub Date : 2024-08-30 DOI: arxiv-2408.17137

Wouter Deleersnyder, Evert Slob

引用次数: 0

Fully Coupled Implicit Hydro-Mechanical Multiphase Flow Simulation in Deformable Porous Media Using DEM 利用 DEM 进行可变形多孔介质中的全耦合隐式水力机械多相流模拟

arXiv - PHYS - Geophysics Pub Date : 2024-08-30 DOI: arxiv-2408.17100

Quanwei Dai, Kang Duan, Chung-Yee Kwok

{"title":"Fully Coupled Implicit Hydro-Mechanical Multiphase Flow Simulation in Deformable Porous Media Using DEM","authors":"Quanwei Dai, Kang Duan, Chung-Yee Kwok","doi":"arxiv-2408.17100","DOIUrl":"https://doi.org/arxiv-2408.17100","url":null,"abstract":"Knowledge of the underlying mechanisms of multiphase flow dynamics in porous\u0000media is crucial for optimizing subsurface engineering applications like\u0000geological carbon sequestration. However, studying the micro-mechanisms of\u0000multiphase fluid--grain interactions in the laboratory is challenging due to\u0000the difficulty in obtaining mechanical data such as force and displacement.\u0000Transitional discrete element method models coupled with pore networks offer\u0000insights into these interactions but struggle with accurate pressure prediction\u0000during pore expansion from fracturing and efficient simulation during the slow\u0000drainage of compressible fluids. To address these limitations, we develop an\u0000advanced two-way coupled hydro-mechanical discrete element method model that\u0000accurately and efficiently captures fluid--fluid and fluid--grain interactions\u0000in deformable porous media. Our model integrates an unconditionally stable\u0000implicit finite volume approach, enabling significant timesteps for advancing\u0000fluids. A pressure-volume iteration scheme dynamically balances\u0000injection-induced pressure buildup with substantial pore structure deformation,\u0000while flow front-advancing criteria precisely locate the fluid--fluid interface\u0000and adaptively refine timesteps, particularly when capillary effects block\u0000potential flow paths. The model is validated against benchmark Hele-Shaw\u0000experiments in both rigid and deformable porous media, providing quantitative\u0000insights into the micro-mechanisms governing multiphase flow. For the first\u0000time, grain-scale inputs such as viscous and capillary pressures, energies,\u0000contact forces, and flow resistances are utilized to provide a detailed\u0000understanding of micro-scale fluid--fluid and fluid--grain flow patterns and\u0000their transitions.","PeriodicalId":501270,"journal":{"name":"arXiv - PHYS - Geophysics","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Information theory, Signal Analysis and Inverse Problem 信息论、信号分析和逆问题

arXiv - PHYS - Geophysics Pub Date : 2024-08-29 DOI: arxiv-2408.16361

Dominique Gibert, Fernando Lopes, Vincent Courtillot, Jean-Baptiste Boulé

引用次数: 0

Composition, Structure and Origin of the Moon 月球的组成、结构和起源

arXiv - PHYS - Geophysics Pub Date : 2024-08-29 DOI: arxiv-2408.16840

Paolo A. Sossi, Miki Nakajima, Amir Khan

{"title":"Composition, Structure and Origin of the Moon","authors":"Paolo A. Sossi, Miki Nakajima, Amir Khan","doi":"arxiv-2408.16840","DOIUrl":"https://doi.org/arxiv-2408.16840","url":null,"abstract":"Here we critically examine the geophysical and geochemical properties of the\u0000Moon in order to identify the extent to which dynamical scenarios satisfy these\u0000observations. New joint inversions of existing lunar geophysical data (mean\u0000mass, moment of inertia, and tidal response) assuming a laterally- and\u0000vertically homogeneous lunar mantle show that, in all cases, a core with a\u0000radius of 300$pm$20 km ($sim$0.8 to 1.5 % the mass of the Moon) is required.\u0000However, an Earth-like Mg# (0.89) in the lunar mantle results in core densities\u0000(7800$pm$100 kg/m$^3$) consistent with that of Fe-Ni alloy, whereas FeO-rich\u0000compositions (Mg# = 0.80--0.84) require lower densities (6100$pm$800\u0000kg/m$^3$). Geochemically, we use new data on mare basalts to reassess the bulk\u0000composition of the Moon for 70 elements, and show that the lunar core likely\u0000formed near 5 GPa, 2100 K and $sim$1 log unit below the iron-w\"ustite buffer.\u0000Moreover, the Moon is depleted relative to the Earth's mantle in elements with\u0000volatilities higher than that of Li, with this volatile loss likely having\u0000occurred at low temperatures (1400$pm$100 K), consistent with mass-dependent\u0000stable isotope fractionation of moderately volatile elements (e.g., Zn, K, Rb).\u0000The identical nucleosynthetic (O, Cr, Ti) and radiogenic (W) isotope\u0000compositions of the lunar and terrestrial mantles, strongly suggest the two\u0000bodies were made from the same material, rather than from an Earth-like\u0000impactor. Rb-Sr in FANs and Lu-Hf and Pb-Pb zircon ages point Moon formation\u0000close to $sim$4500 Ma. Taken together, there is no unambiguous geochemical or\u0000isotopic evidence for the role of an impactor in the formation of the Moon,\u0000implying perfect equilibration between the proto-Earth and Moon-forming\u0000material or alternative scenarios for its genesis.","PeriodicalId":501270,"journal":{"name":"arXiv - PHYS - Geophysics","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reconciling the irreconcilable: window-based versus stochastic declustering algorithms 调和不可调和的矛盾：基于窗口的算法与随机去聚类算法

arXiv - PHYS - Geophysics Pub Date : 2024-08-29 DOI: arxiv-2408.16491

I. Spassiani, S. Gentili, R. Console, M. Murru, M. Taroni, G. Falcone

引用次数: 0

Microstructural characterization to reveal evidence of shock deformation in a Campo del Cielo meteorite fragment 显微结构表征揭示坎波德尔谢洛陨石碎片冲击变形的证据

arXiv - PHYS - Geophysics Pub Date : 2024-08-29 DOI: arxiv-2408.16901

Graeme J. Francolini, Thomas B. Britton

{"title":"Microstructural characterization to reveal evidence of shock deformation in a Campo del Cielo meteorite fragment","authors":"Graeme J. Francolini, Thomas B. Britton","doi":"arxiv-2408.16901","DOIUrl":"https://doi.org/arxiv-2408.16901","url":null,"abstract":"The study of meteorites and their microstructures is a topic which spans\u0000multiple fields of research, such as meteoritics and materials science. For\u0000materials scientists and engineers, the extreme and unusual conditions which\u0000these microstructures form allow for insight into materials which would exist\u0000at the edge of our thermomechanical processing abilities. One such\u0000microstructure found in low-shock event iron meteorites is Neumann bands. These\u0000bands are an array of lenticular deformation twins that form throughout the\u0000Fe-Ni matrix with numerous intersections, resulting in many high stress and\u0000strain regions within the material's surface. The existence of these regions\u0000and the shocks that formed them encourage atypical strain accommodating\u0000mechanisms and structural changes of the material. However, direct\u0000investigation of the deformation twin intersections and the microstructural\u0000behaviour in and around these regions has been limited. In this work,\u0000investigation of these regions in a Campo del Cielo meteorite fragment, with\u0000electron backscatter diffraction (EBSD) and forescatter electron (FSE) imaging,\u0000revealed two primary findings: high-intensity pattern doubling mirrored across\u0000the {110} band at twin-twin intersection and microband formation across the\u0000sample surface, which suggest multilayer twinning and constraint of the crystal\u0000structure at points of twin-twin intersection. Microbands were found to form\u0000along the {110} plane and in regions near Neumann bands. The simultaneous\u0000existence of Neumann bands (microtwins) and microbands is presented here for a\u0000BCC material, and it is believed the Neumann band and microbands formed during\u0000different types and/or shock events. The presence of both Neumann bands and\u0000microbands within a BCC iron meteorite is previously unreported and may be\u0000valuable in furthering our understanding of shock deformation within iron-based\u0000materials.","PeriodicalId":501270,"journal":{"name":"arXiv - PHYS - Geophysics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0