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| Avedik, Felix; Combe, Robert. |
| Elimination of bubble pulses has been the main concern of air gun users for the past years. Until now, the proposed solutions: divided chambers, spheres, have resulted in an appreciable loss of acoustic energy. The Casios-Simplon Water Gun, developed by CNEXO and SODERA, solved this problem using surprisingly simple means, which not only eliminate the disturbing secondary effects (bubbles) but greatly increase the acoustic efficiency of the air gun. The system uses the air gun as a pneumatic accelerator and creates the acoustic pulse by implosion. The emitted signal is free of disturbing secondary effects and its power spectrum closely approaches the spectrum of dynamite type sources. [NOT CONTROLLED OCR] |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1973 |
URL: http://archimer.ifremer.fr/doc/1973/publication-4977.pdf |
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| Patriat, Martin; Klingelhoefer, Frauke; Aslanian, Daniel; Contrucci, Isabelle; Gutscher, Marc-andré; Talandier, Jacques; Avedik, Felix; Francheteau, Jean; Weigel, Wilfried. |
| [1] In French Polynesia, the young (< 5Ma) Society Islands appear to result from intraplate volcanism, while the old (>50 Ma) Tuamotu plateau was likely created at or near the ridge axis. The structure of the crust between those two archipelagoes is constrained by a 300 km long refraction seismic profile. Crustal and upper mantle arrivals recorded by 6 OBHs and 3 land stations were used to provide a 2D model of the crust. Results of our study, combined with that of Grevemeyer et al. [2001] show a slight flexure below the Tahiti apron, while a deep crustal root (21 km) underlies the Tuamotu plateau. These structures reflect the different modes of load emplacement and compensation mechanisms between these two volcanic edifices, consistent with an... |
| Tipo: Text |
Palavras-chave: Volcanic Islands; Flexure; Hotspot; Refraction methods; French Polynesia. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-621.pdf |
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| Duennebier, Fk; Stephen, R; Gettrust, Jf; Avedik, Felix; Ballard, J Alan; Bibee, L Dale; Fehler, Michael; Inderbitzen, Anton; Jacobsen, Randall; Pascal, Georges. |
| Tipo: Text |
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| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/00318/42927/42428.pdf |
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| Avedik, Felix. |
| Detecting and localizing nuclear blasts was an essential stimulus of the actions undertaken in the 1960's to emplace seismological observatories on the seafloor. The plate-tectonic theory, in which the oceanic areas play a major role, greatly accelerated the evolution of modern oceanology. The contribution of Ifremer's department of Marine Geosciences, in helping to advance this area of research, has been significant since 1972. The need for refraction studies to explore the deep structure of the margins and ocean-continent transition zones led us to design a deep-sea Ocean Bottom Seismograph (OBS) MK I in 1975, rated to 6,000 metres depth. This system introduced, for the first time, the concept of "isolated seismic sensors". This principle was adopted... |
| Tipo: Text |
Palavras-chave: Geology; Seismometers; Digital records; Seismology; Surveys; Marine technology; Seismic data. |
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1140.pdf |
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| Avedik, Felix; Renard, V.. |
| Seismic refraction at sea and on continental shelves requires most of all a precise positioning of the shooting and receiving stations and a good signal to noise ratio. A new system has been developed using detectors anchored on the sea floor and radio transmission of signal for refraction work on continental shelves. This technique satisfies both requirements. The system has been tested in the western Channel in December 1971. [NOT CONTROLLED OCR] |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1972 |
URL: http://archimer.ifremer.fr/doc/1972/publication-5125.pdf |
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