@article{fdi:010042514,
  title = {{N}onlinear variations of the physical properties along the southern {E}cuador subduction channel : results from depth-migrated seismic data},
  author = {{A}lcinoe, {C}.{B}. and {S}allares, {V}. and {C}ollot, {J}ean-{Y}ves and {S}age, {F}. and {R}anero, {C}.{R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e use two high-quality pre-stack depth-migrated multichannel seismic profiles acquired to quantify physical properties variations of underthrust sediments along the first similar to 30 km of subduction off the erosional southern {E}cuadorian margin. {S}eismic data show three zones along the subduction channel (referred to as {Z}ones {I}, {II} and {III}) characterized by distinct velocity and velocity-derived physical properties, which are in agreement with values estimated from experimental results of deformation in granular media. {T}hese three zones result from transformational changes of underthrust sediments governed by fundamentally different physical processes that control their mechanical behavior at increasing confining pressures. {B}ased on our observations and its comparison with experimental results, we argue that the transformations undergone by underthrust sediments as they dip into the subduction zone are the following: within {Z}one {I}, progressively increasing velocity (and decreasing velocity-derived porosity) indicates continuous sediment compaction, which must be accompanied by effective fluid drainage along the decollement and/or across the accretionary wedge. {T}he underthrust material is here unconsolidated from a mechanical point of view. {L}aboratory experiments indicate that the dominant processes at this range of pressures are grain rolling, particle rotation and frictional slip at grain contacts. {W}ithin {Z}one {II}, velocity (and porosity) remains constant for similar to 16 km ({SIS}-72) and similar to 12 km ({SIS}-18). {T}his suggests undrained conditions resulting in growing fluid overpressure at the subduction channel. {G}rain deformation is similar to {Z}one {I}. {W}ithin {Z}one {III}, velocity increases and porosity falls rapidly, indicating sediment compaction and subsequent release of over-pressured fluids, where grain deformation is likely to be elastic. {T}his might be the dominant process until the grains attain their crushing strength, resulting in granular cataclasis and, eventually, in the collapse of the system. {W}e suggest that over-pressured fluid release may induce hydrofracturation and it is likely to increase inter-plate coupling down from {Z}one {III}.},
  keywords = {subduction channel ; velocity inversion ; fluid overpressure ; grain deformation},
  booktitle = {},
  journal = {{E}arth and {P}lanetary {S}cience {L}etters},
  volume = {267},
  numero = {3-4},
  pages = {453--467},
  ISSN = {0012-821{X}},
  year = {2008},
  DOI = {10.1016/j.epsl.2007.11.061},
  URL = {https://www.documentation.ird.fr/hor/fdi:010042514},
}