Building Objective 3D Fault Representations in Active Tectonic Settings
Shaw, John H.
Date of Issue2017
Earth Observatory of Singapore
Developing 3D representations of active faults is an important step to improve seismic‐hazard assessment. However, the geometries of faults can be difficult to constrain at depth, and building representations is often subjective. We present a new objective workflow to build 3D fault geometries from surface and subsurface data that are generally available in active tectonic environments. We use surface traces, focal mechanism orientations, and relocated hypocenters as geological constraints in an implicit modeling approach. This method enables us to control the weights assigned to the different constraints, increasing the accuracy of the fault model. We evaluate and refine our method by applying it to a well‐known natural case study: the Puente Hills thrust fault, a blind thrust beneath Los Angeles, California, that is imaged by high‐quality seismic reflection data and that generated the 1987 Mw 6.0 Whittier Narrows earthquake. Then, we apply our new workflow to the Xianshuihe–Anninghe left‐lateral strike‐slip fault systems, China. Implementing this workflow allows for the development of improved fault surface representations that can contribute to Community Fault Models and support fault system modeling, rupture simulations, and regional hazard assessments.
3D fault geometries
Seismological Research Letters
© 2017 Seismological Society of America (SSA). This paper was published in Seismological Research Letters and is made available as an electronic reprint (preprint) with permission of Seismological Society of America (SSA). The published version is available at: [http://dx.doi.org/10.1785/0220160192]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.