Deep crustal structure of the sheared South African continental margin: first results of the Agulhas-Karoo Geoscience Transect

2007 ◽  
Vol 110 (2-3) ◽  
pp. 393-406 ◽  
Author(s):  
N. Parsiegla ◽  
K. Gohl ◽  
G. Uenzelmann-Neben
2004 ◽  
Vol 25 (3-4) ◽  
pp. 283-304 ◽  
Author(s):  
Wilfried Jokat ◽  
Oliver Ritzmann ◽  
Christian Reichert ◽  
Karl Hinz

2015 ◽  
Vol 2015 (1) ◽  
pp. 1-3
Author(s):  
Abdulrhman H. Alghamdi ◽  
Alan R.A. Aitken ◽  
Michael C. Dentith

Geology ◽  
1988 ◽  
Vol 16 (6) ◽  
pp. 533 ◽  
Author(s):  
K.M.M. Rohr ◽  
B. Milkereit ◽  
C. J. Yorath

2015 ◽  
Vol 186 (4-5) ◽  
pp. 331-351 ◽  
Author(s):  
Alexandra Afilhado ◽  
Maryline Moulin ◽  
Daniel Aslanian ◽  
Philippe Schnürle ◽  
Frauke Klingelhoefer ◽  
...  

Abstract Geophysical data acquired on the conjugate margins system of the Gulf of Lion and West Sardinia (GLWS) is unique in its ability to address fundamental questions about rifting (i.e. crustal thinning, the nature of the continent-ocean transition zone, the style of rifting and subsequent evolution, and the connection between deep and surface processes). While the Gulf of Lion (GoL) was the site of several deep seismic experiments, which occurred before the SARDINIA Experiment (ESP and ECORS Experiments in 1981 and 1988 respectively), the crustal structure of the West Sardinia margin remains unknown. This paper describes the first modeling of wide-angle and near-vertical reflection multi-channel seismic (MCS) profiles crossing the West Sardinia margin, in the Mediterranean Sea. The profiles were acquired, together with the exact conjugate of the profiles crossing the GoL, during the SARDINIA experiment in December 2006 with the French R/V L’Atalante. Forward wide-angle modeling of both data sets (wide-angle and multi-channel seismic) confirms that the margin is characterized by three distinct domains following the onshore unthinned, 26 km-thick continental crust : Domain V, where the crust thins from ~26 to 6 km in a width of about 75 km; Domain IV where the basement is characterized by high velocity gradients and lower crustal seismic velocities from 6.8 to 7.25 km/s, which are atypical for either crustal or upper mantle material, and Domain III composed of “atypical” oceanic crust. The structure observed on the West Sardinian margin presents a distribution of seismic velocities that is symmetrical with those observed on the Gulf of Lion’s side, except for the dimension of each domain and with respect to the initiation of seafloor spreading. This result does not support the hypothesis of simple shear mechanism operating along a lithospheric detachment during the formation of the Liguro-Provencal basin.


2006 ◽  
Vol 5 (3) ◽  
pp. 183-186
Author(s):  
R.A. Street ◽  
D.J. Christian ◽  
W.I. Clarkson ◽  
A.C. Cameron ◽  
B. Enoch ◽  
...  

The WASP consortium is conducting an ultra-wide field survey of stars between 8–15 mag from both hemispheres. Our primary science goal is to detect extra-solar ‘hot-Jupiter’-type planets that eclipse (or transit) bright host stars and for which further detailed investigation will be possible. We summarize the design of the SuperWASP instruments and describe the first results from our northern station SW-N, sited in La Palma, Canary Islands. Our second station, which began operations this year, is located at the South African Astronomical Observatory. Between April and September, 2004, SW-N continuously observed ~6.7 million stars. The consortium's custom-written, fully automated data reduction pipeline has been used to process these data, and the information is now stored in the project archive, held by the Leicester database and archive service (LEDAS). We have applied a sophisticated, automated algorithm to identify the low-amplitude (~0.01 mag), brief (~few hours) signatures of transiting exoplanets. In addition, we have assessed each candidate in the light of all available catalogue information in order to reject data artefacts and astrophysical false positive detections. The highest priority candidates are currently being subjected to further observations in order to select the true planets. Once the exoplanets are confirmed, a host of exciting opportunities are open to us. In this paper, we describe two techniques that exploit the transits in order to detect other objects within the same system. The first involves determining precise epochs for a sequence of transit events in order to detect the small timing variations caused by the gravitational pull of other planets in the same system. The second method employs ultra-high precision photometry of the transits to detect the deviations caused by the presence of exoplanetary moons. Both of these techniques are capable of detecting objects the size of terrestrial planets.


Tectonics ◽  
2018 ◽  
Vol 37 (5) ◽  
pp. 1576-1604 ◽  
Author(s):  
M. Druet ◽  
A. Muñoz-Martín ◽  
J. L. Granja-Bruña ◽  
A. Carbó-Gorosabel ◽  
J. Acosta ◽  
...  

Author(s):  
Frauke Klingelhoefer ◽  
Jacques Déverchère ◽  
David Graindorge ◽  
Chafik Aïdi ◽  
Rabie Badji ◽  
...  

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