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| Titel |
First images of the crustal structure across the eastern Algerian margin, from deep penetrating seismic data. |
| VerfasserIn |
Boualem Bouyahiaoui, Abdeslam Abtout, Françoise Sage, Frauke Klingelhoeffer, Jean-Yves Collot, Abdelkarim Yelles-Chaouche, Abbas Marok, Hamou Djellit, Audrey Galves, Rabah Bracène, Philippe Schnurle, David Graindorge, Scientific party |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250075713
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| Zusammenfassung |
| The Algerian continental margin North Africa presents one of only a few examples of a
passive continental margin formed in a back-arc environment, which undergoes current
compression and is proposed to be reactivated today. In the framework of the Algerian –
French SPIRAL research program (Sismique Profonde et Investigation Regionale du nord de
l’ALgérie), a seismic cruise was conducted on the R/V Atalante from September to
November 2009. During the cruise, deep penetrating low frequency multichannel and
wide-angle seismic data were acquired in order to study the deep structure of the Algerian
margin. In this work, we present the preliminary results from wide-angle modeling of the
North-east Algerian margin in the region of Annaba along a N-S transect using a data set of
42 OBS (ocean bottom seismometers) along a profile extending 117km, and 13 broadband
seismological stations along a profile of 80 km length. Travel-time tomography and
forward modeling were undertaken to model the velocity structure in this region. The
resulting velocity models image the thickness of the sedimentary layers, which
varies between a few hundred meters on the continental margin of more than 4 km
in the basin. The crust is about 6 km thick in the basin, and thickens to 7-8 km
between 40 and 60km distance from the margin toe. Crustal thickness increases
to about 22 km at the continental slope over a distance of ~ 90 km. The nature
of the crust was determined to be thin oceanic with abnormal velocity gradient
in the basin, and thinned continental from around 30 km distance from the coast
landward.
Integration of the wide-angle seismic data with multichannel seismic, gravity and
magnetic data will help to better understand the structure of the Algerian margin and the
adjacent oceanic basin in the Annaba region, and to discuss the numerous cinematic
models proposed in literature regarding the formation of the north-Algerian basin. |
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