 |
| Titel |
A seismic wide angle profile across the Lesser Antilles Arc south of Guadeloupe |
| VerfasserIn |
W. Weinzierl, H. Kopp, E. Flueh, D. Klaeschen, THALES Working Group |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250025557
|
|
|
|
|
|
| Zusammenfassung |
| We present the results of a 280km long regional wide-angle seismic
profile conducted in the Lesser Antilles. The profile crosses an
active island arc, the Tiburon Ridge and one of the largest
accretionary complexes in the world. Crustal thickness beneath the
island arc is ~25km and 8km beneath the Accretionary Prism suggesting
oceanic crust below. We present a statistical separation strategy to
explore velocity-depth Model space derived from the inversion of
seismic refraction data. The profile crossing the Island arc can be
characterized by three tectonic entities, namely the accretionary
complex, active and inactive island arc. By perturbing the model space
(v,z) as well as the transition zones in between it is possible to
sample the model space and compare the results of inversion of this
monte carlo ensemble. We invert more than 20000 first arrival travel
times in over 50 starting Models to enhance the statistical resolution
of the final average model. The deeper portions of this transect could
be confined by forward modelling of the wide angle data. The island
arc shows intracrustal as well as Moho reflections where the upper
crust is approximately 13km thick and the lower crust 8km. The island
arc backstop shows considerable topography and is approximately
10-20km in width. The Accretionary wedge extends more than 100km from
the deformation front to the backstop and shows strong attenuation of
signal penetration. |
|
|
|
|
|
|