Multichannel Seismic Imaging of the Rivera Plate Subduction at the Seismogenic Jalisco Block Area (Western Mexican Margin)
Por:
Bartolome, Rafael, Gorriz, Estefania, Danobeitia, Juanjo, Cordoba, Diego, Marti, David, Cameselle, Alejandra L., Nunez-Cornu, Francisco, Bandy, William L., Mortera-Gutierrez, Carlos A., Nunez, Diana, Castellon, Arturo, Luis Alonso, Jose
Publicada:
1 oct 2016
Resumen:
During the TSUJAL marine geophysical survey, conducted in February and
March 2014, Spanish, Mexican and British scientists and technicians
explored the western margin of Mexico, considered one of the most active
seismic zones in America. This work aims to characterize the internal
structure of the subduction zone of the Rivera plate beneath the North
American plate in the offshore part of the Jalisco Block, to link the
geodynamic and the recent tectonic deformation occurring there with the
possible generation of tsunamis and earthquakes. For this purpose, it
has been carried out acquisition, processing and geological
interpretation of a multichannel seismic reflection profile running
perpendicular to the margin. Crustal images show an oceanic domain,
dominated by subduction-accretion along the lower slope of the margin
with a subparallel sediment thickness of up to 1.6 s two-way travel time
(approx. 2 km) in the Middle American Trench. Further, from these data
the region appears to be prone to giant earthquake production. The top
of the oceanic crust (intraplate reflector) is very well imaged. It is
almost continuous along the profile with a gentle dip (< 10A degrees);
however, it is disrupted by normal faulting resulting from the bending
of the plate during subduction. The continental crust presents a
well-developed accretionary prism consisting of highly deformed
sediments with prominent slumping towards the trench that may be the
result of past tsunamis. Also, a bottom simulating reflector (BSR) is
identified in the first half a second (twtt) of the section. High
amplitude reflections at around 7-8 s twtt clearly image a discontinuous
Moho, defining a very gentle dipping subduction plane.
Filiaciones:
Bartolome, Rafael:
CSIC, Inst Ciencias Mar, P Maritimo Barceloneta 37-49, E-08003 Barcelona, Spain
Gorriz, Estefania:
CSIC, Inst Ciencias Mar, P Maritimo Barceloneta 37-49, E-08003 Barcelona, Spain
Univ Barcelona, Marti i Franques S-N, E-08028 Barcelona, Spain
Danobeitia, Juanjo:
CSIC, Unidad Tecnol Marina, P Maritimo Barceloneta 37-49, E-08003 Barcelona, Spain
Cordoba, Diego:
Univ Complutense Madrid, Ciudad Univ,Plaza Ciencias S-N, E-28040 Madrid, Spain
Marti, David:
Inst Ciencias Tierra Jaume Almera, C Lluis Sole Sabaris S-N, Barcelona 08028, Spain
Cameselle, Alejandra L.:
CSIC, Inst Ciencias Mar, P Maritimo Barceloneta 37-49, E-08003 Barcelona, Spain
Nunez-Cornu, Francisco:
CUC, Av Univ 203, Del Ixtapa 48280, Puerto Vallarta, Mexico
Bandy, William L.:
Univ Nacl Autonoma Mexico, Inst Geofis, Ciudad Univ, Mexico City 04510, DF, Mexico
Mortera-Gutierrez, Carlos A.:
Univ Nacl Autonoma Mexico, Inst Geofis, Ciudad Univ, Mexico City 04510, DF, Mexico
Nunez, Diana:
CUC, Av Univ 203, Del Ixtapa 48280, Puerto Vallarta, Mexico
Castellon, Arturo:
CSIC, Unidad Tecnol Marina, P Maritimo Barceloneta 37-49, E-08003 Barcelona, Spain
Luis Alonso, Jose:
CSIC, Unidad Tecnol Marina, P Maritimo Barceloneta 37-49, E-08003 Barcelona, Spain
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