When, where and how does the co-to postseismic transition occur?

Task manager: A. Sladen
Participants: A. Sladen, B. Delouis, J.M. Nocquet, M. Vergnolle, O. Cavalié, A. Avallone, M. Marchandon, T. Ragon, Q. Bletery, V. Monteiller.

Work Package 2 is dedicated to the implementation and application of new techniques of kinematic modeling and inversion to retrieve the distribution and history of co- and postseismic slip on the fault. We will investigate the impact of more realistic forward models on the accuracy of the data prediction and evaluate their impact on the inverted slip model. We will also use a full Bayesian approach to perform the slip inversion and provide model uncertainties. Finally, we will develop a consistent co- to postseismic inversion scheme to better establish the spatial relation between seismic and aseismic slip. These kinematic results are required to provide insights on frictional properties of the fault plane and to discuss and constrain mechanical models of the fault and surrounding medium behavior, topics that will be addressed in WP3.

Our objective is to obtain:

• Modeling and kinematic tools and approaches allowing to better discuss the slip distribution on the fault plane.
• Highlight on the resolution and robustness of slip imagery and quantification of the model uncertainties.
• Imagery of the spatio-temporal relationship between seismic (coseismic) and aseismic (postseismic) slip on the fault (e.g. corelated, anti-correlated, timing).
• Documentation of the kinematic parameters related to slow slip versus fast slip (e.g. slip velocity, slip propagation velocity and direction).