Project #8

Integrating physics-based earthquake rupture models in seismic hazard assessments

Main Supervisor: Alice-Agnes Gabriel (LMU)
Co-Supervisor: Sebastien Hok and Oona Scotti (IRSN), Yann Klinger (IPGP)

Location:Ludwig-Maximilians-Universität München (Germany) –

Duration of the PhD: 3 years

The doctoral candidate will be enrolled in a PhD program at the Ludwig-Maximilians-Universität München

Objectives: Recent, well recorded earthquakes reveal complex fault-ruptures involving many different fault sections. Evaluating the possibility of future complex ruptures in any given fault system remains to this day a major challenge for seismic and surface fault displacement hazard assessments. This project will develop 3D dynamic earthquake rupture scenarios across complex fault systems combining nonlinear frictional failure and seismic wave propagation. Empowered by supercomputing, such models will produce physics-based forecasts of ground motions and surface fault displacement as well as fault interaction, thus providing insight into fundamental processes of earthquake physics. The rich amount of data available in the Central Apennines, Italy, will be used among others to first validate dynamic rupture simulations for chosen recent events integrating data from field work, geodesy, seismology and laboratory data. A special focus will be the characteristics of surface rupture that can shed light on shallow fault rupture processes during earthquakes, which in turn open the way to a better assessment of earthquake surface rupture hazards. This work will use an approach similar to that developed for the modelling of the 2016 Mw7.8 Kaikôura earthquake, New Zealand and the 2016 Norcia, Italy earthquake. In a second step, the doctoral candidate will extract all mechanically viable earthquake rupture scenarios, compute physics-based ground motion models accounting for source/site and path effects, and use this information to construct a range of plausible fault models for hazard assessment using tools such as SHERIFS to explore epistemic uncertainties and OpenQuake Engine to compute seismic hazard at selected sites. Additional research stays at the Scripps Institution of Oceanography, UC San Diego, are possible.

Expected Results:

  1. Physically constrained ground motions and surface ruptures including the exploration of non-linear source-path-site effects in complex dynamic earthquake ruptures;
  2. Physically viable multi fault rupture scenarios constrained by and validated against available data;
  3. Integration of physics-based complex fault rupture scenarios in fault-based seismic and surface fault displacement hazard assessments.

Planned secondments: IPGP (3 months, Y. Klinger, M12-14, Inference of 3D fault geometry from field and geodetic data), IRSN (4 months, S. Hok & O. Scotti, M24-27, Assimilation and validation of 3D models with observations), GEM (1 month, M. Pagani, M30, Integration in operational hazard assessment), Munich-Re (1 month, M. Kaser, M38, Implications for risk models with GeoRisk section).