Lithospheric convective instability could induce creep along part of the San Andreas fault

Abstract

Research Article| September 01, 2013 Lithospheric convective instability could induce creep along part of the San Andreas fault Laetitia Le Pourhiet; Laetitia Le Pourhiet 1Université Pierre-et-Marie-Curie-Paris 06, Institut des Sciences de la Terre, Paris F-75005, France2CNRS, Unité Mixte de Recherche 7193, Paris F-75005, France Search for other works by this author on: GSW Google Scholar Jason Saleeby Jason Saleeby 3Division of Earth and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Laetitia Le Pourhiet 1Université Pierre-et-Marie-Curie-Paris 06, Institut des Sciences de la Terre, Paris F-75005, France2CNRS, Unité Mixte de Recherche 7193, Paris F-75005, France Jason Saleeby 3Division of Earth and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA Publisher: Geological Society of America Received: 18 Nov 2012 Revision Received: 16 Apr 2013 Accepted: 05 May 2013 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2013 Geological Society of America Geology (2013) 41 (9): 999–1002. https://doi.org/10.1130/G34244.1 Article history Received: 18 Nov 2012 Revision Received: 16 Apr 2013 Accepted: 05 May 2013 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Laetitia Le Pourhiet, Jason Saleeby; Lithospheric convective instability could induce creep along part of the San Andreas fault. Geology 2013;; 41 (9): 999–1002. doi: https://doi.org/10.1130/G34244.1 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 SocietyGeology Search Advanced Search Abstract Along the western border of the Sierra Nevada microplate, the San Andreas fault (California, United States) is comprised of three segments. Two (north and south segments) are locked and support large earthquakes (e.g., the M 7.7 1906 San Francisco and the M 7.8 1857 Fort Tejon earthquakes), while the central segment, from Parkfield to San Juan Bautista, is creeping. Based on mechanical models, we show that the late Pliocene–Quaternary convective removal (delamination) of the southern Sierra Nevada mantle lithosphere and associated uplift of the Sierra Nevada Mountains causes the Great Valley upper crust to deform by flexure and buckling. Additional three-dimensional flexural models imply that the local flexural bulge overlaps with the creeping segment of the fault system, while geological observations indicate that the local weakening of the San Andreas fault started at the same time that the Sierra Nevada started its recent phase of uplift. We argue that bending stresses promote lithostatic pore pressure to occur in the depth range of 7–15 km, causing the effective strength of the fault to vanish, and locally favoring creep. Our results suggest for the first time that earthquake cycles along a major plate boundary may be influenced by convective instabilities in the adjacent upper mantle. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.