{"paper_id":"4e09108b-ab95-44bf-a74b-2d3787082649","body_text":"Forward modelling of electrical resistivity and induced polarization in anisotropic media using the spectral-infinite-element method | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Forward modelling of electrical resistivity and induced polarization in anisotropic media using the spectral-infinite-element method Kiana Damavandi, Hom Nath Gharti This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8622978/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract We present a three-dimensional spectral-infinite-element method (SIEM) for simulating direct current resistivity and induced polarization (IP) in complex anisotropic media. Our method accommodates fully anisotropic and arbitrary conductivity structures. To accurately represent the unbounded domain, infinite boundary conditions are incorporated into the weak formulation of the governing Poisson equation. An anisotropic two-layer earth model is used to validate the SIEM implementation, and resistivity responses are compared to analytical solutions and the AIM4RES software package. The numerical results show reliable accuracy, with an average relative error below 9%. Additional validation is performed by comparing chargeability responses with finite-element and finite-volume results. Tilted transverse isotropy significantly distorts potential fields and complicates data interpretation, whereas vertical transverse isotropy has a negligible effect and enables accurate anomaly localization, according to tests conducted on a flat model with a conductive target. Lastly, to investigate the combined effects of anisotropy and topography, 3D IP forward modelling is performed over uneven terrain for different dipping anisotropy angles. The results show that increasing the dipping angle increases the likelihood of misinterpretation. Physical sciences/Engineering Physical sciences/Mathematics and computing Physical sciences/Physics Earth and environmental sciences/Solid earth sciences Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-8622978\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":true,\"archivedVersions\":[],\"articleType\":\"Article\",\"associatedPublications\":[],\"authors\":[{\"id\":578577530,\"identity\":\"434d74c2-0b65-4e48-8bcb-a6163a328264\",\"order_by\":0,\"name\":\"Kiana Damavandi\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Queen's University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Kiana\",\"middleName\":\"\",\"lastName\":\"Damavandi\",\"suffix\":\"\"},{\"id\":578577532,\"identity\":\"97e51022-6785-4acf-95dd-6a02113b7eb5\",\"order_by\":1,\"name\":\"Hom Nath Gharti\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAuklEQVRIiWNgGAWjYBACAyA+8IFULYwHZ5CqhfkwD0lazKXbLxy2KTssxy/d/kyCocaOsBbLOWcKDuecO2wsOeeMmQTDsWQiHHYjJ+FwbtvhxA03ctgkGBuYidRi2Xa4fv+N9GdALfXEaEk/cJix7XCCgUSCGVDLYaJsYTjYcy7dcMaNHGOLhGPHibLl8YcfZdby/DPSH974UFNNWAsDAw8watig7ARiNDAwsD9AaBkFo2AUjIJRgA0AAIXaPSFjiifCAAAAAElFTkSuQmCC\",\"orcid\":\"\",\"institution\":\"Queen's University\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Hom\",\"middleName\":\"Nath\",\"lastName\":\"Gharti\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2026-01-17 02:38:27\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-8622978/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-8622978/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":100945530,\"identity\":\"47495173-2baf-4016-876e-dc19bbb1f217\",\"added_by\":\"auto\",\"created_at\":\"2026-01-23 06:11:35\",\"extension\":\"json\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":4539,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"2209959bc235476eb2cc51e1b2612cc6.json\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8622978/v1/9c034f626c0f829f06dcfea0.json\"},{\"id\":104402740,\"identity\":\"d7c42044-d171-4707-835f-03293b1297af\",\"added_by\":\"auto\",\"created_at\":\"2026-03-11 12:16:16\",\"extension\":\"pdf\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":3971863,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"ForwardmodellingofelectricalresistivityandinducedpolarizationinanisotropicmediausingthespectralinfiniteelementmethodR1.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8622978/v1_covered_856fda39-dee1-4179-a18e-5097c3fe4e23.pdf\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"Forward modelling of electrical resistivity and induced polarization in anisotropic media using the spectral-infinite-element method\",\"fulltext\":[],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":false,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":true,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":true,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":true,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true},\"keywords\":\"\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-8622978/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-8622978/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"We present a three-dimensional spectral-infinite-element method (SIEM) for simulating direct current resistivity and induced polarization (IP) in complex anisotropic media. 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Lastly, to investigate the combined effects of anisotropy and topography, 3D IP forward modelling is performed over uneven terrain for different dipping anisotropy angles. 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