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| Becel, A.; Laigle, Mireille; Diaz, J.; Montagner, J. -p.; Hirn, A.. |
| Three unburied ocean bottom seismometers (OBS) equipped with Trillium 240 s broad-band seismometers recorded spheroidal free oscillations of the Earth out to periods over 1000 s period, for the M = 8.1, April 1, 2007 Solomon Islands earthquake. In contrast to broadband observatories of the global network that operate in quiet continental locations, these instruments were dropped on the several-km thick layer of sediments of the forearc and accretionary wedge of the Lesser Antilles subduction zone. Furthermore, a high ambient noise level due to the ocean surface infragravity waves is expected to cover the frequency band of Earth's normal modes band when recorded at these sites. In spite of these hostile environmental conditions, the frequency of clearly... |
| Tipo: Text |
Palavras-chave: Lesser Antilles; Broadband seismology; Free oscillations; Ocean bottom seismometers. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00185/29606/27971.pdf |
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| Bayrakci, Gaye; Laigle, Mireille; Becel, A.; Hirn, A.; Taymaz, T.; Yolsal-cevikbilen, S.. |
| A 3-D tomographic inversion of first arrival times of shot profiles recorded by a dense 2-D OBS network provides an unprecedented constraint on the P-wave velocities heterogeneity of the upper-crustal part of the North Marmara Trough (NMT), over a region of 180 km long by 50 km wide. One of the specific aims of this controlled source tomography is to provide a 3-D initial model for the local earthquake tomography (LET). Hence, in an original way, the controlled source inversion has been performed by using a code dedicated to LET. After several tests to check the results trade-off with the inversion parameters, we build up a 3-D a priori velocity model, in which the sea-bottom topography, the acoustic and the crystalline basements and the Moho interfaces... |
| Tipo: Text |
Palavras-chave: Body waves; Seismic tomography; Continental tectonics: strike-slip and transform; Crustal structure.. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00185/29601/28033.pdf |
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| Geli, Louis; Henry, P.; Grall, Celine; Tary, Jean-baptiste; Lomax, A.; Batsi, Evangelia; Riboulot, Vincent; Cros, Estelle; Gurbuz, C.; Isik, S. E.; Sengor, A. M. C.; Le Pichon, X.; Ruffine, Livio; Dupre, Stephanie; Thomas, Yannick; Kalafat, D.; Bayrakci, G.; Coutellier, Q.; Regnier, Thibaut; Westbrook, Graham; Saritas, H.; Cifci, G.; Cagatay, M. N.; Ozeren, M. S.; Gorur, N.; Tryon, M.; Bohnhoff, M.; Gasperini, L.; Klingelhoefer, Frauke; Scalabrin, Carla; Augustin, Jean-marie; Embriaco, D.; Marinaro, G.; Frugoni, F.; Monna, S.; Etiope, G.; Favali, P.; Becel, A.. |
| Understanding micro-seismicity is a critical question for earthquake hazard assessment. Since the devastating earthquakes of Izmit and Duzce in 1999, the seismicity along the submerged section of North Anatolian Fault within the Sea of Marmara (comprising the “Istanbul seismic gap”) has been extensively studied in order to infer its mechanical behaviour (creeping vs locked). So far, the seismicity has been interpreted only in terms of being tectonic-driven, although the Main Marmara Fault (MMF) is known to strike across multiple hydrocarbon gas sources. Here, we show that a large number of the aftershocks that followed the M 5.1 earthquake of July, 25th 2011 in the western Sea of Marmara, occurred within a zone of gas overpressuring in the 1.5–5 km depth... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00439/55072/56500.pdf |
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