@article{fdi:010070238,
  title = {{S}ubducted oceanic relief locks the shallow megathrust in central {E}cuador},
  author = {{C}ollot, {J}ean-{Y}ves and {S}anclemente, {E}. and {N}ocquet, {J}ean-{M}athieu and {L}epretre, {A}. and {R}ibodetti, {A}lessandra and {J}arrin, {P}. and {C}hlieh, {M}ohamed and {G}raindorge, {D}. and {C}harvis, {P}hilippe},
  editor = {},
  language = {{ENG}},
  abstract = {{W}hether subducted oceanic reliefs such as seamounts promote seismic rupture or aseismic slip remains controversial. {H}ere we use swath bathymetry, prestack depth-migrated multichannel seismic reflection lines, and wide-angle seismic data collected across the central {E}cuador subduction segment to reveal a broad similar to 55kmx50km, similar to 1.5-2.0km high, low height-to-width ratio, multipeaked, sediment-bare, shallow subducted oceanic relief. {O}wing to {L}a {P}lata {I}sland and the coastline being located, respectively, similar to 35km and similar to 50-60km from the trench, {GPS} measurements allow us to demonstrate that the subducted oceanic relief spatially correlates to a shallow, similar to 80kmx55km locked interplate asperity within a dominantly creeping subduction segment. {T}he oceanic relief geometrical anomaly together with its highly jagged topography, the absence of a subduction channel, and a stiff erosive oceanic margin are found to be long-term geological characteristics associated with the shallow locking of the megathrust. {A}lthough the size and level of locking observed at the subducted relief scale could produce an {M}-w >7+ event, no large earthquakes are known to have happened for several centuries. {O}n the contrary, frequent slow slip events have been recorded since 2010 within the locked patch, and regular seismic swarms have occurred in this area during the last 40years. {T}hese transient processes, together with the rough subducted oceanic topography, suggest that interplate friction might actually be heterogeneous within the locked patch. {A}dditionally, we find that the subducted relief undergoes internal shearing and produces a permanent flexural bulge of the margin, which uplifted {L}a {P}lata {I}sland. {P}lain {L}anguage {S}ummary {S}ubducted seamounts play an important but still uncertain role in earthquake rupture processes, as seamounts are considered to subduct either aseismically or seismically. {W}e use marine geophysical data across the central {E}cuador convergent margin to reveal a broad similar to 55kmx50km, similar to 1.5-2.0km high, shallow subducted oceanic relief of the {C}arnegie {R}idge. {N}ew {GPS} measurements collected on {L}a {P}lata {I}sland and along the {E}cuador coast allow us to demonstrate that the subducted oceanic relief spatially correlates to a shallow, similar to 80kmx55km locked interplate asperity within a dominantly creeping subduction segment. {T}he oceanic relief geometrical anomaly together with its rough topography and the stiff oceanic {E}cuador margin are found to be long-term geological characteristics associated with the shallow locking of the plate interface. {A}lthough the size and level of locking observed at the subducted relief scale could produce an {M}-w >7+ event, no large earthquake but frequent slow slip events and associated seismic swarms occurred within the locked patch. {T}hese transient processes together with the rough subducted oceanic topography support the view of a heterogeneous interplate frictional pattern within the locked patch. {O}n a regional scale, the subduction of the oceanic relief has deformed the {E}cuador margin and uplifted {L}a {P}lata {I}sland.},
  keywords = {seamount subduction ; interseismic coupling ; seismic imaging ; slow slip event ; megathrust earthquake ; {EQUATEUR} ; {ANDES} ; {PACIFIQUE} ; {LA} {PLATA} {ILE}},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch : {S}olid {E}arth},
  volume = {122},
  numero = {5},
  pages = {3286--3305},
  ISSN = {2169-9313},
  year = {2017},
  DOI = {10.1002/2016jb013849},
  URL = {https://www.documentation.ird.fr/hor/fdi:010070238},
}