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Harmonic Fluctuation of the Slope of the Frequency–Magnitude Distribution (b‐Value) as a Function of the Angle of Rake

2018; Seismological Society of America; Volume: 108; Issue: 4 Linguagem: Inglês

10.1785/0120170328

1943-3573

Antonio Petruccelli, Gianfranco Vannucci, Barbara Lolli, Paolo Gasperini,

High-pressure geophysics and materials

Research Article| June 05, 2018 Harmonic Fluctuation of the Slope of the Frequency–Magnitude Distribution (⁠b‐Value) as a Function of the Angle of Rake Antonio Petruccelli; Antonio Petruccelli aDipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat 8, I‐40127 Bologna, Italy, antonio.petruccelli4@unibo.itpaolo.gasperini@unibo.it Search for other works by this author on: GSW Google Scholar Gianfranco Vannucci; Gianfranco Vannucci bIstituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, Via Donato Creti 12, I‐40128 Bologna, Italy, gianfranco.vannucci@ingv.itbarbara.lolli@ingv.it Search for other works by this author on: GSW Google Scholar Barbara Lolli; Barbara Lolli bIstituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, Via Donato Creti 12, I‐40128 Bologna, Italy, gianfranco.vannucci@ingv.itbarbara.lolli@ingv.it Search for other works by this author on: GSW Google Scholar Paolo Gasperini Paolo Gasperini aDipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat 8, I‐40127 Bologna, Italy, antonio.petruccelli4@unibo.itpaolo.gasperini@unibo.itcAlso at Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, Via Donato Creti 12, I‐40128 Bologna, Italy. Search for other works by this author on: GSW Google Scholar Author and Article Information Antonio Petruccelli aDipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat 8, I‐40127 Bologna, Italy, antonio.petruccelli4@unibo.itpaolo.gasperini@unibo.it Gianfranco Vannucci bIstituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, Via Donato Creti 12, I‐40128 Bologna, Italy, gianfranco.vannucci@ingv.itbarbara.lolli@ingv.it Barbara Lolli bIstituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, Via Donato Creti 12, I‐40128 Bologna, Italy, gianfranco.vannucci@ingv.itbarbara.lolli@ingv.it Paolo Gasperini aDipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat 8, I‐40127 Bologna, Italy, antonio.petruccelli4@unibo.itpaolo.gasperini@unibo.itcAlso at Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, Via Donato Creti 12, I‐40128 Bologna, Italy. Publisher: Seismological Society of America First Online: 05 Jun 2018 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (4): 1864–1876. https://doi.org/10.1785/0120170328 Article history First Online: 05 Jun 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Antonio Petruccelli, Gianfranco Vannucci, Barbara Lolli, Paolo Gasperini; Harmonic Fluctuation of the Slope of the Frequency–Magnitude Distribution (⁠b‐Value) as a Function of the Angle of Rake. Bulletin of the Seismological Society of America 2018;; 108 (4): 1864–1876. doi: https://doi.org/10.1785/0120170328 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract Previous works suggested that the slope (⁠b‐value) of the frequency–magnitude distribution of earthquakes might significantly vary as a function of the style of faulting. In this work, we resume such hypothesis using improved datasets and procedures and by testing a simple harmonic functional form of the b‐value as a function of the angle of rake λ⁠.Using the Global Centroid Moment Tensor (CMT) catalog updated to the middle of 2016, we reliably compute the b‐value over 12 nonoverlapping rake windows with width γ=30° showing a clear oscillating behavior with highs for normal and lows for reverse mechanisms. We also test the existence of a spatial link between variations of the style of faulting and of the b‐value by determining the rake and the b‐value separately from the Global CMT catalog and from a magnitude homogenized version of the bulletin of the International Seismological Centre, respectively, based on a spatial tessellation of the Earth's surface.For both approaches, we verify, using two statistical methods, that the b‐values computed from earthquakes with different tectonic styles are actually different from each other for many combinations of rakes and particularly for all combinations of almost pure tectonic styles.We find that the fitted harmonic function has zero phase and unit frequency, thus indicating that b‐value modulation is about proportional to −sinλ⁠. Because the latter corresponds to the dot product between the unit versors of the coseismic displacement and of the gravity force component along the fault plane, b‐value modulation appears to be about proportional to the work done by the gravity force during the fault slip. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.