We couple a geodynamic seismic cycle code to a dynamic rupture code in order to assess the influence of both long term tectonics and short term wave propagation on rupture path selection in subduction zones. The coupling of these two codes is the first link in the ASCETE modelling framework.
Brizzi et al., (GRL, in review) found that subduction mega-earthquakes favour long subduction zones with high sediment supply. They used multivariate statistics on a global subduction zone characteristics database. To further assess the correlation and possible causality between mega-earthquakes and sediment thickness at the trench, numerical models are developed for a parameter study into sediment thickness in subduction zones. This project is in collaboration with Silvia Brizzi (first author), and Francesca Funiciello (Roma Tre University, Rome, Italy).
We complement a global earthquake database that contains subduction zone characteristics (Heuret et al., 2011) with tsunami data. We statistically analyse the database to identify tectonic parameters that affect tsunamigenesis. To assess the causality, we resort to numerical modelling.
Simulations of subduction zone earthquakes based on purely elastic seafloor displacements typically underestimate the potential seafloor displacement and hence the ensuing tsunami. We use dynamic rupture simulations to analyse whether plastic energy dissipation is a missing rheological component that could account for larger surface displacements. This project is in collaboration with Stephanie Wollherr (first author), Alice-Agnes Gabriel, Elizabeth Madden, and Thomas Ulrich (LMU Munich, Munich, Germany).
We are developing a benchmark setup with the ASCETE project for a subduction zone seismic cycle model coupled to a dynamic rupture model of a single earthquake, then coupled to a tsunami propagation and inundation model. Elizabeth Madden (LMU Munich, Munich, Germany) is taking the lead on this project.
A series of 3D dynamic rupture models along the plate interface that hosted the 2004 M 9.1-9.3 Sumatra-Andaman earthquake is explored to assess the influence of different initial stress conditions. The STM code provides one of the initial stress conditions from a 2D numerical setup of the hypocenter of the Sumatra-Andaman earthquake. The dynamic rupture models suggest high fluid pressures and low differential stress for this earthquake. This project is in collaboration with Elizabeth Madden (first author), Thomas Ulrich, and Alice-Agnes Gabriel (LMU Munich, Munich, Germany).
We compile global databases on outer rise seismicity, fault characteristics, and intermediate depth seismicity to discover a definite link between intermediate depth and outer rise seismicity. This project is in collaboration with the ORCHID group that was established at CIDER 2017.