@article{fdi:010085881,
  title = {{D}eep mass redistribution prior to the 2010 {M}w 8.8 {M}aule ({C}hile) {E}arthquake revealed by {GRACE} satellite gravity},
  author = {{B}ouih, {M}. and {P}anet, {I}. and {R}{\'e}my, {D}ominique and {L}onguevergne, {L}. and {B}onvalot, {S}ylvain},
  editor = {},
  language = {{ENG}},
  abstract = {{S}ubduction zones megathrust faults constitute a considerable hazard as they produce most of the world's largest earthquakes. {H}owever, the role in megathrust earthquake generation exerted by deeper subduction processes remains poorly understood. {H}ere, we analyze the 2003 - 2014 space-time variations of the {E}arth's gravity gradients derived from three datasets of {GRACE} geoid models over a large region surrounding the rupture zone of the {M}w 8.8 {M}aule earthquake. {I}n all these datasets, our analysis reveals a large-amplitude gravity gradient signal, progressively increasing in the three months before the earthquake, {N}orth of the epicentral area. {W}e show that such signals are equivalent to a 60 km(3) water storage decrease over 2 months and cannot be explained by hydrological sources nor artefacts, but rather find origin from mass redistributions within the solid {E}arth on the continental side of the subduction zone. {T}hese gravity gradient variations could be explained by an extensional deformation of the slab around 150-km depth along the {N}azca {P}late subduction direction, associated with large-scale fluid release. {F}urthermore, the lateral migration of the gravity signal towards the surface from a low coupling segment around -32.5 degrees {N}orth to the high coupling one in the {S}outh suggests that the {M}w 8.8 earthquake may have originated from the propagation up to the trench of this deeper slab deformation. {O}ur results highlight the importance of observations of the {E}arth's time-varying gravity field from satellites in order to probe slow mass redistributions in-depth major plate boundaries and provide new information on dynamic processes in the subduction system, essential to better understand the seismic cycle as a whole.},
  keywords = {gravity gradients ; {GRACE} ; earthquake ; signal separation ; {CHILI} ; {MAULE}},
  booktitle = {},
  journal = {{E}arth and {P}lanetary {S}cience {L}etters},
  volume = {584},
  numero = {},
  pages = {117465 [12 ]},
  ISSN = {0012-821{X}},
  year = {2022},
  DOI = {10.1016/j.epsl.2022.117465},
  URL = {https://www.documentation.ird.fr/hor/fdi:010085881},
}