Investigating and validating surface rupture characteristics with rupture dynamics on faults with shallow complexities

Sebastien Hok, Rihab Sassi, & Yann Klinger

Submitted August 15, 2018, SCEC Contribution #8620, 2018 SCEC Annual Meeting Poster #203

Earthquake surface rupture style can take many forms, ranging from a sharp cut in the landscape to a wide distribution of cracks. This complexity is related to several physical parameters (either average or local parameters of the rupture) that we can investigate with rupture dynamics: e.g. focal mechanism, number and geometry of existing faults, local variations of stresses and stress drop at depth and along strike, as well as local subsurface properties.

Surface rupture hazard for critical facilities is currently estimated from empirical datasets by averaging and mixing available data and controlling parameters. Therefore physics-based rupture models can help to better compute site-specific estimations, taking into account the local properties that control the final surface slip. For instance, prior knowledge of the fault network and geometries can be used to evaluate the secondary rupture probabilities and amount of slip.

Before being used for hazard assessment, the physics-based rupture models need a careful validation step. For that reason, within the recently funded research project DISRUPT, we are starting implementing dynamic surface rupture models to compare their results with observations of surface rupture and deformation. With its exceptional dataset covering a 200km-long rupture trace, the 2013 Baluchistan earthquake exhibits several interesting configurations of surface rupture patterns to validate models and provide new insights on surface rupture mechanisms (segmentation, partitioning, off-fault deformation). We have started studying the impact of fault geometrical complexities on the distributed slip occurrence around the main fault, and specifically fault dip angle change close to the surface. We will also investigate the link between dynamic stresses and surface rupture partitioning.

Key Words
Surface rupture, Rupture dynamics

Hok, S., Sassi, R., & Klinger, Y. (2018, 08). Investigating and validating surface rupture characteristics with rupture dynamics on faults with shallow complexities. Poster Presentation at 2018 SCEC Annual Meeting.

Related Projects & Working Groups
Fault and Rupture Mechanics (FARM)