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Cros, Estelle; Geli, Louis. |
The main objective of the present post-doctoral study aims at improving the fine-scale characterization of earthquakes within the submerged section of the North-Anatolian fault, in the western part of Sea of Marmara, using the data recorded by a network of ten Ocean Bottom Seismometers (OBSs) deployed by Ifremer, between April and August, 2011. Manual picks on all individual OBSs were thus considered, in order to avoid artifacts resulting from LTA/STA algorithms. A high-resolution, 3D velocity model was used, with a node spacing of 750 m x 750 m x 200 m. Special focus was been given on the characterization of the aftershock sequence that followed the Mw 5.2 earthquake that occurred on July, 25th, 2011 on top of the Western High, in the area where gas... |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00278/38916/37456.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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Gürbüz, Cemil; Isik, Sezim Ezgi; Geli, Louis; Cros, Estelle. |
A study was carried out within Work Package 8 (WP8) of MARSITE in order to improve the characterization of the near-fault micro-seismicity within the Sea of Marmara. Velocity models were thus developed by KOERI and Ifremer respectively, following two different approaches: - KOERI developed a 3D velocity model for the whole Marmara Region (within latitudes 39.5°N - 42.5°N and longitudes 26.0°E - 30.5°E), including land and seabottom stations, with grid spacing of 9 km x 9 km x 3 km. - Ifremer developed an opposite, but complementary approach, strictly based on seabottom stations, for the Western Sea of Marmara (40°43’N - 40°54’N - 27°30’E - 28°15’E). A high resolution velocity model with a 750 m x 750 m x 400 m grid spacing was built, using multibeam... |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00278/38915/37455.pdf |
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Vandemeulebrouck, J.; Roux, Philippe; Cros, Estelle. |
Old Faithful Geyser in Yellowstone National Park (USA) has attracted numerous scientific investigations for over two centuries to better understand its geological structure, the physics of its eruptions, and the controls of its intermittency. Using data acquired with a seismic array in 1992, we track the sources of hydrothermal tremor produced by boiling and cavitation inside the geyser. The location of seismic sources identifies a previously unknown lateral cavity at 15m below the surface, on the SW side of the vent, and connected to the conduit. This reservoir is activated at the beginning of each geyser eruption cycle and plays a major role in the oscillatory behavior of the water level in the conduit before each eruption. |
Tipo: Text |
Palavras-chave: Geyser; Hydrothermal; Seismology; Old Faithful; Tremor. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00171/28263/26703.pdf |
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