Evaluating models of Coulomb stress transfer: Is variable fault geometry important?. Issue 24 (26th December 2016)

• Record Type: Journal Article
• Authors: Mildon, Zoe K.; Toda, Shinji; Faure Walker, Joanna P.; Roberts, Gerald P.
• Is Part Of: Geophysical research letters. Volume 43:Issue 24(2016)
• Page Start: 12, 407
• Page End: 12, 414
• Publication Date: 2016-12-26
• Subjects: Coulomb stress transfer -- normal faults -- variable fault geometry; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL071128
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: To determine the importance of receiver fault geometry in Coulomb stress calculations a new methodology is presented to model faults with variable geometry. Although most models use planar faults, it is known that these are inaccurate representations of faults observed in the field. The central Italian Apennines are chosen as a straightforward tectonic system with well‐exposed normal faults to investigate the effect of variable geometry. It is shown that the static Coulomb stress transfer is most sensitive to changes in strike of the receiver faults, rather than changes in dip and rake. Therefore, a novel methodology to generate strike‐variable faults composed of discrete rectangular patches is developed. Using the 2009 L'Aquila earthquake ( Mw = 6.3) the calculated stress transferred to planar versus variable faults is assessed. The stress transferred to variable faults is sufficiently different when compared to planar cases to merit other earthquake sequences being reassessed with available fault geometry. Key Points: Current Coulomb stress models of planar faults are not representative of true fault geometries New method presented here creates strike‐variable faults from many rectangular patches that works within Coulomb 3.4 There are substantial differences between planar versus strike‐variable fault transferred stresses so past earthquakes should be re‐examined