New time-dependent slip inversion of Slow Slip Events: application to the 2006 Guerrero SSE

The 2006 Slow Slip Event in Guerrero, Mexico, is one of the world's largest SSE observed up to now. Thanks to the development of the Guerrero GPS network, the 2006 event was recorded at 15 continuous GPS stations that allowed a detailed study of the surface displacements produced by the event. Temporal variations of the displacement vectors, observed during the 2006 SSE, suggest a complex spatio-temporal evolution of slip on the plate interface. We developed a new method to model the spatial and temporal evolution of slip on the fault plane. We assume a functional form for the slip function on the fault plane, similar to the slip function defined by Liu et al. (2006) for kinematic source inversion of regular earthquakes. This slip function is parameterized by the slip amplitude, the initiation time of the slip, and the slip duration, which is the combination of an accelerating and decelerating rise time. The fault plane is divided in 42 subfaults of 78 km x 25 km each. The Green functions are calculated for a layered elastic half space. First, forward modeling tests show that the geodetic data are sensible to the location of the initiation slip patch, the propagation of the rupture and the duration of the slip. Second, using the same parameterization for the slip function, we invert for the slip amplitude, slip duration and rupture propagation velocity. We perform a linearized least-square inversion in the frequency domain. This new inversion procedure provides a continuous image of the spatial and temporal variatio