Coulomb stress variations associated with slow slip, tectonic tremor, and seismicity along the northern Hikurangi Margin, New Zealand

Friday, 19 December 2014
Erin K Todd, University of California Santa Cruz, Santa Cruz, CA, United States, Charles A Williams, GNS Science-Institute of Geological and Nuclear Sciences Ltd, Lower Hutt, New Zealand, Stephen C Bannister, GNS Science, Lower Hutt, New Zealand, Susan Y Schwartz, University of California-Santa Cruz, Santa Cruz, CA, United States and Laura M Wallace, University of Texas at Austin, Institute for Geophysics, Austin, TX, United States
We investigate the spatiotemporal relationships between slow slip, tectonic tremor, and earthquakes along the northern Hikurangi Margin, New Zealand. Using a recently developed geometry of the Hikurangi subduction interface along with PyLith, a finite-element crustal deformation modeling tool, to simulate slow slip along the Hikurangi Margin, New Zealand, we present analysis of the resulting Coulomb stress changes along the megathrust and on surrounding faults in both the along-dip and along-strike directions. Using slip histories for shallow (<15 km depth) slow slip events from the northern Hikurangi Margin in 2010, the slip will be applied to the model at a single time step, as though it were a traditional earthquake, as well as at multiple time steps to analyze the Coulomb stress changes over time. The spatial and temporal evolution of slow slip induced Coulomb stress changes are considered with respect to earthquakes from the GeoNet catalog relocated using NonLinLoc, a probabilistic, non-linear, 3D earthquake location software, and tremor detected using envelope cross correlation and located with a 3D grid search.