Geometrical barrier determines the updip limit of slow earthquake slip

Geometrical barrier determines the updip limit of slow earthquake slip | 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 Geometrical barrier determines the updip limit of slow earthquake slip Takeshi Akuhara, Kazuya Shiraishi, Takeshi Tsuji, Yusuke Yamashita, and 15 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4591362/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 03 Jan, 2026 Read the published version in Nature Communications → Version 1 posted You are reading this latest preprint version Abstract Increased observations of shallow slow earthquakes have highlighted structural irregularities that explain the generation mechanisms of slow earthquakes. However, due to considerable uncertainties in the source locations of slow earthquakes, it is unclear what controls the spatial extent of slow earthquakes and what hinders slip propagation on the megathrust. We utilize the precise locations of tectonic tremors, bathymetry data, and seismic reflection images acquired from the Kumano-nada in the Nankai Trough subduction zone to investigate structural factors that determine the spatial extent of tectonic tremors. Results suggest that an abrupt change in the dip angle of the megathrust, located at the point where the frontal thrust branches from the décollement, behaves as a geometrical barrier to along-dip slip propagation. An underplated structure likely generates a pore fluid pressure contrast near this branching point, further strengthening this barrier. In addition, we find that a similar geometrical barrier created by deep-rooted strike-slip faults may affect along-strike slip propagation. Furthermore, the absence of slow earthquakes in the eastern part of the study area is attributed to a stress shadow on the rear side of the subducting Paleo–Zenith ridge. Earth and environmental sciences/Solid Earth sciences/Seismology Earth and environmental sciences/Solid Earth sciences/Tectonics Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Published Journal Publication published 03 Jan, 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. 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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-4591362","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":335206119,"identity":"c71d6dc5-9aa6-4e03-b91e-b261c7e31290","order_by":0,"name":"Takeshi 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