Dynamics of non-self-similar earthquakes illuminated by a controlled fault asperity

Dynamics of non-self-similar earthquakes illuminated by a controlled fault asperity | 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 Dynamics of non-self-similar earthquakes illuminated by a controlled fault asperity Kurama Okubo, Futoshi Yamashita, Eiichi Fukuyama This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6553961/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 30 Apr, 2026 Read the published version in Nature Communications → Version 1 posted You are reading this latest preprint version Abstract Most ordinary earthquakes follow self-similar scaling, where source duration scales with the one-third power of seismic moment. However, some earthquake clusters show non-self-similar scaling, where source duration remains nearly constant regardless of seismic moment. Their source mechanisms, previously proposed to involve fixed source dimensions with variable stress drop or accelerating rupture velocity, are not fully validated due to uncertainties in estimating source properties, often caused by observational biases such as path effects. Here, we present a robust dynamic source model for non-self-similar earthquakes based on laboratory experiments with size- and shape-controlled sources. A thin circular gouge patch, placed on the meter-scale laboratory fault, generated microearthquakes exhibiting non-self-similar scaling, with magnitudes ranging from M w -7.3 to -6.0. A dynamic rupture model, constrained by the observed source parameters and the controlled source configuration, suggests that such scaling arises from a combination of variable stress drop and self-healing friction, even without a substantial rupture barrier confining the final source size. Therefore, non-self-similar earthquakes are not limited to specific environments, such as velocity-weakening patches on creeping faults, but can occur in a broader range of tectonic settings, wherever slip is governed by self-healing friction on isolated asperity patches with variable stress drop. Earth and environmental sciences/Solid Earth sciences/Seismology Earth and environmental sciences/Solid Earth sciences/Geophysics Earth and environmental sciences/Solid Earth sciences/Tectonics earthquake scaling non-self-similar earthquakes friction experiments foreshocks dynamic rupture model Full Text Additional Declarations There is NO Competing Interest. Supplementary Files OkuboetalSIlinenocorrected17459757392.pdf Supplementary Information Cite Share Download PDF Status: Published Journal Publication published 30 Apr, 2026 Read the published version in Nature Communications → 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-6553961","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":452218287,"identity":"6a2e8c68-4d50-4a78-b26d-8b727563f158","order_by":0,"name":"Kurama Okubo","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0klEQVRIiWNgGAWjYBACCQY2BmYGBpsEEOcAiGBsIE5LGulaDicQ7zDJ9rY06YKK83n8/IcfHmD4ZcPAPJuANdI8x45Jzzhzu1hyRprBAca+NAbGOQfwa5GTSG+T5m27nbjhBgNQS89hBsYZBBwJ1XIuccP54x+I0yItkXYMqOVA4oYDOQYHGH4QoUWy51iy9YwzyUC/5BQcSGxI4yHoF4njbYa3CyrsgCF2fPOHD39s5AwJhRgqSGxj4DGcQYoOBoY/DAzyEqRpGQWjYBSMguEPAHUBRu8jY34eAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0001-6453-8238","institution":"National Research Institute for Earth Science and Disaster Resilience","correspondingAuthor":true,"prefix":"","firstName":"Kurama","middleName":"","lastName":"Okubo","suffix":""},{"id":452218288,"identity":"ad738546-99e0-4a7f-8980-07916af3d444","order_by":1,"name":"Futoshi Yamashita","email":"","orcid":"https://orcid.org/0000-0001-9938-3766","institution":"National Research Institute for Earth Science and Disaster Resilience","correspondingAuthor":false,"prefix":"","firstName":"Futoshi","middleName":"","lastName":"Yamashita","suffix":""},{"id":452218289,"identity":"4ae5e800-8f12-4627-9143-f6dc58b854ee","order_by":2,"name":"Eiichi Fukuyama","email":"","orcid":"","institution":"Department of Civil and Earth Resources Engineering, Kyoto University","correspondingAuthor":false,"prefix":"","firstName":"Eiichi","middleName":"","lastName":"Fukuyama","suffix":""}],"badges":[],"createdAt":"2025-04-29 08:05:24","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6553961/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6553961/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41467-026-72217-x","type":"published","date":"2026-04-30T04:00:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":108495114,"identity":"1ac52cd1-cded-401e-baeb-1d57a86b9b59","added_by":"auto","created_at":"2026-05-05 10:08:51","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1897892,"visible":true,"origin":"","legend":"Article File","description":"","filename":"Okuboetalmainlinenocorrected17459757391.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6553961/v1_covered_ef5d9550-96a3-485b-97b0-3485a526e793.pdf"},{"id":82125304,"identity":"1204c80a-09c8-4270-9e45-c43951fe3dd1","added_by":"auto","created_at":"2025-05-07 03:47:59","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":5636659,"visible":true,"origin":"","legend":"Supplementary Information","description":"","filename":"OkuboetalSIlinenocorrected17459757392.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6553961/v1/4e3d0b49b3a6211babd91feb.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Dynamics of non-self-similar earthquakes illuminated by a controlled fault asperity","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"earthquake scaling, non-self-similar earthquakes, friction experiments, foreshocks, dynamic rupture model","lastPublishedDoi":"10.21203/rs.3.rs-6553961/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6553961/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Most ordinary earthquakes follow self-similar scaling, where source duration scales with the one-third power of seismic moment. 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