The state of pore fluid pressure and 3D megathrust earthquake dynamics
KAUST Grant NumberORS-2017-CRG6 3389.02
Permanent link to this recordhttp://hdl.handle.net/10754/668865
MetadataShow full item record
AbstractThe importance of pore fluid pressure (Pf ) for fault strength, stress state and slip behavior holds promise for explaining spatio-temporal subduction zone megathrust be19 havior, but the coseismic state of Pf and its distribution with depth are poorly constrained. Here, we analyze fault stress states and 3D rupture dynamics of six scenarios based on the 2004 Mw 9.1 Sumatra-Andaman earthquake. We vary Pf from hydrostatic to litho22 static under two di↵erent gradients that result in depth-dependent versus constant ef23 fective normal stress on the seismogenic part of the megathrust. As Pf magnitude in24 creases, fault strength, moment magnitude, cumulative slip, peak slip rate, dynamic stress drop and rupture velocity decrease. When Pf follows the lithostatic gradient, depth-constant e↵ective normal stress results, as theoretically proposed. We find that such a near-lithostatic pore fluid pressure gradient shifts peak slip and peak slip rate up-dip
CitationMadden, E., Ulrich, T., & Gabriel, A.-A. (2021). The state of pore fluid pressure and 3D megathrust earthquake dynamics. doi:10.31223/x5rw3b
SponsorsWe would like to thank Dmitry Garagash and Taras Gerya for helpful discussions, as well as the participants of the 2019 SZ4D MCS RCN Megathrust Modeling Workshop in Eu669 gene, Oregon. Simulations were conducted using the open-source software package Seis670 Sol, freely available at github.com/SeisSol/SeisSol. All simulation input and output files will be made accessible at the zenodo data repository. During the review process, the data is accessible here: https://bit.ly/3uuJUks. The authors acknowledge funding from the Volkswagen Foundation (project “ASCETE”, grant no. 88479), the European Union’s Horizon 2020 research and innovation program (TEAR ERC Starting grant no. 852992 and ChEESE Center of Excellence, grant no. 823844), the German Research Foun676 dation (DFG) (projects GA 2465/2-1, GA 2465/3-1), by KAUST-CRG (FRAGEN, grant no. ORS-2017-CRG6 3389.02), by KONWIHR – the Bavarian Competence Network for Technical and Scientific High Performance Computing (project NewWave), and by Bay679 Lat – the Bavarian University Centre for Latin America. Computing resources were pro680 vided by the Institute of Geophysics of LMU Munich (Oeser et al., 2006) and the Leib681 niz Supercomputing Centre (LRZ, projects no. pr63qo and pr45fi).
PublisherCalifornia Digital Library (CDL)