The project aims at taking benefit of the fault empirical data and knowledge that we have gained over the last decades, and of our strong experience in earthquake modeling (dynamic rupture and Ground Motion), to develop a new generation of rupture and Ground Motion models, based on a novel paradigm: 3D fault zones with generic macroscopic properties whose inhomogeneous and anisotropic characters evolve depending on both overall and along-strike fault maturity. These new models will be tightly rooted in natural fault observations –those already available and the new ones we plan to acquire, and we will check at all steps that the models reproduce the observations on earthquakes; this cross-validation between model outputs and observations is rarely performed at the present time. We expect that integrating actual fault source properties in rupture models will decrease the discrepancies between models outputs and natural earthquake behavior, whereas the fault-based Ground Motion computations will significantly reduce the present uncertainties on the anticipated Ground Motions.

Furthermore, finding out that most major fault properties are deterministic, even generic, implies that those properties result from some common, scale-invariant physics. The understanding of that physics should advance generic earthquake and Ground Motion models that could be run for the vast majority of faults and earthquakes worldwide. These new models will thus open a novel avenue in earthquake modeling and understanding and in hazard assessment. To start following this new route, we propose to carry a pilot study where prior knowledge on fault properties is introduced as constraining inputs into Earthquake Early Warning codes that we have developed. We expect that introducing prior knowledge on faults prone to break and prior likely rupture scenarios might contribute to reduce uncertainties on the real time warning of ground shaking.

To reach our objectives, our approach is four-fold:

Task 1 ‘Measuring fault damage and deriving elastic properties in natural damage zones’
Task 2 ‘Building generic 3D dynamic rupture models integrating generic fault properties’
Task 3 ‘Estimating Ground Motions from generic rupture models and assessing uncertainties’
Task 4 ‘Integrating fault data and prior earthquake scenarios and Ground Motion in Earthquake Early Warning’