@article{fdi:010049658,
  title = {{M}ass-transport deposits in the northern {E}cuador subduction trench : result of frontal erosion over multiple seismic cycles},
  author = {{R}atzov, {G}ueorgui and {C}ollot, {J}ean-{Y}ves and {S}osson, {M}. and {M}igeon, {S}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}nvestigations of {M}ass-{T}ransport {D}eposits ({MTD}s) and turbidite deposition in the confined {N}orth {E}cuador subduction trench provide access to paleoseismic information and insights into long-term mechanisms for frontal tectonic erosion at a convergent margin. {T}he studied trench has been the site of four great subduction earthquakes (7.7 <= {M}w <= 8.8) during the 20th century. {T}he trench is isolated from major continental sediment input, so that investigated {MTD}s and turbidites are considered of local origin. {S}wath bathymetry, seismic reflection and {C}hirp data, together with sedimentary cores and {C}-14 dating revealed that seven {MTD}s were emplaced in distinct trench sub-basins since similar to 23 kyr, and 27 turbidites deposited in the southernmost trench sub-basin since similar to 4.9 kyr. {O}ur analysis shows that six {MTD}s were derived from the margin, while a single one stemmed from the outer trench wall. {T}emporal correlations between {MTD}s emplaced within trench sub-basins separated by a structural saddle, indicate that the seven {MTD}s were emplaced during five main events. {T}hree were triggered locally and tentatively dated 5.8, 1.6 kyr and {R}ecent, whereas four were emplaced in distinct trench sub-basins as a result of two regional events at 22.6 and 15.4 kyr. {N}one of the {MTD}s occurred during the fast stage of the last sea-level rise (similar to 13 to 8 kyr). {H}owever, dissociation of gas hydrates during the last 8 kyr-stage of slow sea-level rise might have contributed to trigger the three youngest {MTD}s. {T}he large 1.5-13.5 kyr return time of the {MTD}s contrasts with that of 189 yr of the turbidites. {T}he later is consistent with the 73 yr return time of two local {M}w 8.2 earthquakes, implying that turbidites might have been triggered by large earthquakes. {T}he very large {MTD}s return time is attributed to long-term deformation processes and mechanical weakening of the margin outer wedge, in response to repeated variations in basal friction, pore pressure and margin extensional/contraction strain over multiple earthquake cycles. {T}his process contributes to short-term frontal erosion, the rate of which is estimated to be 8.6 . 10(-3) km(3)/kyr/km, since at least 15.4 kyr.},
  keywords = {mass-transport deposit ; turbidite ; earthquake ; subduction ; erosion ; seismic cycle},
  booktitle = {},
  journal = {{E}arth and {P}lanetary {S}cience {L}etters},
  volume = {296},
  numero = {1-2},
  pages = {89--102},
  ISSN = {0012-821{X}},
  year = {2010},
  DOI = {10.1016/j.epsl.2010.04.048},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049658},
}