georefid:2012-021567SEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContact2013-07-08T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=10.1029/2010GL046002<gco:CharacterString>High-velocity frictional properties of clay-rich fault gouge in a megasplay fault zone, Nankai subduction zone</gco:CharacterString>2010-01-01publicationgeorefid:2012-021567doi:10.1029/2010GL046002Ujiie, KohtaroUniversity of Tsukuba, Graduate School of Life and Environmental Sciences, Tsukuba, JapanauthorTsutsumi, AkitoKyoto University, JapanauthorAmerican Geophysical Union, Washington, DC, United StatespublisherdocumentDigitalGeophysical Research Letters37 (24)We conducted high-velocity friction experiments on clay-rich fault gouge taken from the megasplay fault zone in the Nankai subduction zone under dry and wet conditions. In the dry tests, dehydration of clay minerals occurred by frictional heating, and slip weakening is related to thermal pressurization associated with water vaporization, resulting in a random distribution of clay-clast aggregates in the gouge matrix. In the wet tests, slip weakening is caused by pore-fluid pressurization via shear-enhanced compaction and frictional heating, and there is a very weak dependence of the steady-state shear stress on the normal stress. The resulting microstructure reflects the grain size segregation in a granular-fluid shear flow at high shear rates. These results suggest that earthquake rupture propagates easily through clay-rich fault gouge by high-velocity weakening, potentially leaving the microstructures resulting from the frictional heating or the flow sorting at high slip rates.completedGeophysics of minerals and rocksAsiaclay mineralsFar Eastfault zonesfaultsfrictiongougegrain sizeHonshuilliteIntegrated Ocean Drilling ProgramIODP Site C0004JapanKii PeninsulaNankai TroughNanTroSEIZENorth PacificNorthwest PacificP-T conditionsPacific Oceanphysical propertiessheet silicatessilicatesslip ratessubduction zonesWest Pacificurn:org.iodp:exp:314:site:C0004urnlargerWorkCitationstudyurn:org.iodp:exp:314urnlargerWorkCitationcampaignurn:org.iodp:exp:316:site:C0004urnlargerWorkCitationstudyurn:org.iodp:exp:316urnlargerWorkCitationcampaignEnglishgeoscientificInformation136.4300136.430033.130033.1300Supplemental information/data is available in the online version of this articleapplication/pdfunknownSEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContacthttp://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1944-8007/homepage/2013Special_Section_Proposal-form.pdfdownload