Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
11024694 | Earth and Planetary Science Letters | 2018 | 13 Pages |
Abstract
We study the rupture processes of Iquique earthquake Mw 8.1 (2014/04/01) and its largest aftershock Mw 7.7 (2014/04/03) that ruptured the North Chile subduction zone. High-rate Global Positioning System (GPS) recordings and strong motion data are used to reconstruct the evolution of the slip amplitude, rise time and rupture time of both earthquakes. A two-step inversion scheme is assumed, by first building prior models for both earthquakes from the inversion of the estimated static displacements and then, kinematic inversions in the frequency domain are carried out taken into account this prior information. The preferred model for the mainshock exhibits a seismic moment of 1.73 Ã 1021 Nm (Mw 8.1) and maximum slip of â¼9 m, while the aftershock model has a seismic moment of 3.88 Ã 1020 (Mw 7.7) and a maximum slip of â¼3 m. For both earthquakes, the final slip distributions show two asperities (a shallow one and a deep one) separated by an area with significant slip deficit. This suggests a segmentation along-dip which might be related to a change of the dipping angle of the subducting slab inferred from gravimetric data. Along-strike, the areas where the seismic ruptures stopped seem to be well correlated with geological features observed from geophysical information (high-resolution bathymetry, gravimetry and coupling maps) that are representative of the long-term segmentation of the subduction margin. Considering the spatially limited portions that were broken by these two earthquakes, our results support the idea that the seismic gap is not filled yet.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Earth and Planetary Sciences (General)
Authors
Jorge Jara, Hugo Sánchez-Reyes, Anne Socquet, Fabrice Cotton, Jean Virieux, Andrei Maksymowicz, John DÃaz-Mojica, Andrea Walpersdorf, Javier Ruiz, Nathalie Cotte, Edmundo Norabuena,