Interseismic fault strengthening and earthquake-slip instability: Friction or cohesion?

Abstract

Research Article| October 01, 2003 Interseismic fault strengthening and earthquake-slip instability: Friction or cohesion? Sankar K. Muhuri; Sankar K. Muhuri 1School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73019, USA Search for other works by this author on: GSW Google Scholar Thomas A. Dewers; Thomas A. Dewers 1School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73019, USA Search for other works by this author on: GSW Google Scholar Thurman E. Scott, Jr.; Thurman E. Scott, Jr. 2Poromechanics Institute, University of Oklahoma, Norman, Oklahoma 73019, USA Search for other works by this author on: GSW Google Scholar Ze'ev Reches Ze'ev Reches 3Institute of Earth Sciences, Hebrew University, Jerusalem 91904, Israel Search for other works by this author on: GSW Google Scholar Author and Article Information Sankar K. Muhuri 1School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73019, USA Thomas A. Dewers 1School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73019, USA Thurman E. Scott, Jr. 2Poromechanics Institute, University of Oklahoma, Norman, Oklahoma 73019, USA Ze'ev Reches 3Institute of Earth Sciences, Hebrew University, Jerusalem 91904, Israel Publisher: Geological Society of America Received: 17 Feb 2003 Revision Received: 09 Jun 2003 Accepted: 12 Jun 2003 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2003) 31 (10): 881–884. https://doi.org/10.1130/G19601.1 Article history Received: 17 Feb 2003 Revision Received: 09 Jun 2003 Accepted: 12 Jun 2003 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Sankar K. Muhuri, Thomas A. Dewers, Thurman E. Scott, Ze'ev Reches; Interseismic fault strengthening and earthquake-slip instability: Friction or cohesion?. Geology 2003;; 31 (10): 881–884. doi: https://doi.org/10.1130/G19601.1 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 The slip instability of an earthquake and its abrupt energy release depend primarily on the intensity of strength drop during accelerated fault slip. This process is typically attributed to changes of frictional resistance between two sliding blocks. Here we show that friction changes alone cannot explain observed strength variations of artificial fault zones. Sandstone samples with saw-cut faults and gypsum gouge zones were subjected to many cycles of hold-slide loading. Samples with water-saturated gouge display (1) systematic, time-dependent increase of gouge strength; (2) unstable failure of gouge with large stress drops; and (3) lithification of gouge by crack sealing, recrystallization, porosity reduction, and grain bonding. All these features are absent in identical tests with dry gouge. These observations indicate that gouge particles are cemented by chemical processes during hold periods and suggest that the cyclical strength variations are controlled by cohesion strengthening rather than by friction changes. We further hypothesize that crustal fault zones could be lithified during the interseismic stage, and this lithification would control earthquake-slip instability. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.