Enigmatic Harmonic Tremors at the Oman Drilling Project Multi-Borehole Observatory: Cultural Noise or Subsurface Gas Flow?

Enigmatic Harmonic Tremors in the Samail Ophiolite: Evidence for Subsurface Gas Flow? | 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 Research Article Enigmatic Harmonic Tremors in the Samail Ophiolite: Evidence for Subsurface Gas Flow? Tianze Liu, Chao Liang, John M. Aiken, Wenbo Wu, Robert Sohn This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8214658/v2 This work is licensed under a CC BY 4.0 License Status: Posted Version 2 posted You are reading this latest preprint version Show more versions Abstract Harmonic tremors are a unique class of seismic signals often attributed to subsurface fluid flow, but can also be generated by anthropogenic processes. We present observations of tremors with a harmonic interval of ~12.75 Hz up to the 15th mode at ~191 Hz during a seismic-acoustic experiment at the Oman Drilling Project Multi-Borehole Observatory, located on an ultramafic terrain of the Samail ophiolite with minimal human activities. The tremors persist for the entire nine-month observation interval, with mode frequencies varying by ~0.1% diurnally and by ~1% overall. We find that the tremor characteristics are inconsistent with signals from documented anthropogenic sources and that sustained gas flow through a fluid-filled, subsurface fracture is the most plausible source mechanism. Our results have potentially important implications for free gas processes during low-temperature serpentinization and motivate further research to investigate the seismic signals generated in these environments. Geophysics Geochemistry Geology harmonic tremor serpentinization subsurface gas flow natural hydrogen ophiolite Full Text Additional Declarations The authors declare no competing interests. Supplementary Files enigmaticharmonictremorssupv4.pdf Cite Share Download PDF Status: Posted Version 2 posted You are reading this latest preprint version Show more versions 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. 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