@article{fdi:43445,
  title = {{A} seismic refraction survey in the {K}erguelen isles, southern {I}ndian {O}cean},
  author = {{R}ecq, {M}. and {C}harvis, {P}hilippe},
  editor = {},
  language = {{ENG}},
  abstract = {{T}wo 65 km long on land refraction lines, with shot detonated at sea, were implemented in the {C}ourbet {P}eninsula, eastern region of the {K}erguelen archipelago ({T}erres {A}ustrales et {A}ntarctiques {F}ran{\c{c}}aises, southern {I}ndian {O}cean). {T}he first profile {P}1, oriented {NE} {SW}, runs from {C}ap {R}atmanoff toward {M}ont {R}oss, and the second one, {P}2, from {P}ointe {S}uzanne, {SE} of the {C}ourbet {P}eninsula, through the {V}al {S}tuder. {D}ata from both profiles were supplemented by using the {B}ouguer gravity anomaly map not previously studied. {T}he data combined standard travel time interpretation, wide angle reflected wave study, synthetic seismograms and {S} wave analysis. {T}he velocity depth behaviour shows that the mean crustal thickness ranges from 14 to 17 km only, varying with the locality. {T}he structure of the crust beneath {K}erguelen resembles those observed beneath aseismic ridges (i.e. the {C}rozet {R}ise and the {M}adagascar {R}idge). {A}verage velocity of 5.5 km s 1 on both lines is in the range of those determined for oceanic layer 2, which is there 8 9 km thick. {A}verage velocity of 6.6 km s 1 is in the range of velocities within oceanic layer 3. {T}he transition to mantle velocity, 7.95 km s 1 is best modelled by a positive velocity gradient within the crust. {T}his feature is similar to that observed on structures generated near spreading centres. {T}hese new data combined with geological and geochemical investigations in the archipelago support an oceanic origin for the {K}erguelen {H}eard {R}idge, and also {B}roken {R}idge. {B}oth structures were joined 40 {M}yr ago, as shown by the magnetic anomaly pattern. {R}efraction studies invalidate the assumption that isostatic compensation is achieved by a 23 km deep crustal root, but substantiate the contribution of a low velocity mantle. {G}ravity data are consistent with refraction studies. {N}o crustal root appears to be present beneath {M}ont {R}oss. {T}he best match between gravity and refraction data in the {V}al {S}tuder is obtained by assuming the presence of a shallow intrusive body, related to the fault and dyke system, and {M}ontagnes {V}ertes plutonic intrusive complex nearby.},
  keywords = {{GEOPHYSIQUE} ; {SISMOLOGIE} ; {SISMIQUE} {A} {REFRACTION} ; {ONDE} {SISMIQUE} ; {PROPAGATION} {D}'{ONDE} ; {GRAVIMETRIE} ; {CARTOGRAPHIE} ; {OCEAN} {INDIEN} ; {KERGUELEN}},
  booktitle = {},
  journal = {{G}eophysical {J}ournal of the {R}oyal {A}stronomical {S}ociety},
  volume = {84},
  numero = {},
  pages = {529--559},
  year = {1986},
  DOI = {10.1111/j.1365-246{X}.1986.tb04370.x},
  URL = {https://www.documentation.ird.fr/hor/fdi:43445},
}