|
|
|
Registros recuperados: 60 | |
|
|
Funck, T; Jackson, H; Louden, K; Klingelhoefer, Frauke. |
[ 1] The Davis Strait transform margin was studied using a 630-km-long wide-angle reflection/ refraction seismic transect extending from SE Baffin Island to Greenland. Dense airgun shots were recorded by 28 ocean bottom seismometers deployed along the line. A P wave velocity model was developed from forward and inverse modeling of the wide-angle data and incorporation of coincident deep multichannel reflection seismic data. Off Baffin Island in the Saglek Basin, 7 to 11-km-thick two-layered continental crust (5.8 - 6.6 km/s) is observed. Off Greenland, continental crust is divided into three layers (5.4 - 6.8 km/s) with a maximum thickness of 20 km. Farther offshore Greenland the crust thins to 7 - 12 km and the lower crust disappears. Between the... |
Tipo: Text |
Palavras-chave: Magmatic underplating; Refraction seismics; Transform margin. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-4393.pdf |
| |
|
|
Menesguen, Claire; Hua, Bach-lien; Carton, Xavier; Klingelhoefer, Frauke; Schnurle, Philippe; Reichert, C.. |
The North Atlantic temperature and salinity distributions are strongly influenced by the existence of Mediterranean eddies (meddies) which significantly contribute to the transport of the warm and salty Mediterranean Water along different pathways. The most common pathways are observed to be North and West of the Canary Current. However, a 2011 seismic reflection cruise conducted by BGR and Ifremer near the North-Western African margin of Morocco, MIRROR Leg 2, revealed the presence of a meddy south of the Azores front and very close to the Morocco coastline. This unusual location of a strong Mediterranean Water anomaly is confirmed by other data. Moreover, meddies are long-lived structures whose dynamics and dissipation are not yet completely understood.... |
Tipo: Text |
|
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00074/18499/16046.pdf |
| |
|
|
Biari, Youssef; Klingelhoefer, Frauke; Sahabi, Mohamed; Aslanian, Daniel; Schnurle, Philippe; Berglar, K.; Moulin, Maryline; Mehdi, K.; Graindorge, D.; Evain, Mikael; Benabdellouahed, Massinissa; Reichert, C.. |
The structure of the Moroccan and Nova Scotia conjugate rifted margins is of key importance for understanding the Mesozoic break-up and evolution of the northern central Atlantic Ocean basin. Seven combined multichannel reflection (MCS) and wide-angle seismic (OBS) data profiles were acquired along the Atlantic Moroccan margin between the latitudes of 31.5° and 33° N during the MIRROR seismic survey in 2011, in order to image the transition from continental to oceanic crust, to study the variation in crustal structure and to characterize the crust under the West African Coast Magnetic Anomaly (WACMA). The data were modeled using a forward modeling approach. The final models image crustal thinning from 36 km thickness below the continent to approximately 8... |
Tipo: Text |
Palavras-chave: Moroccan continental margin; Wide-angle seismic modeling; Deep crustal structure; Ocean continent transition. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00273/38401/36726.pdf |
| |
|
|
Batsi, Evangelia; Lomax, Anthony; Tary, Jean-baptiste; Klingelhoefer, Frauke; Riboulot, Vincent; Murphy, Shane; Monna, Stephen; Ozel, Nurcan Meral; Kalafat, Dogan; Saritas, Hakan; Cifci, Gunay; Cagatay, Namik; Gasperini, Luca; Geli, Louis. |
A detailed study, based on ocean‐bottom seismometers (OBSs) recordings from two recording periods (3.5 months in 2011 and 2 months in 2014) and on a high‐resolution, 3D velocity model, is presented here, which provides an alternative view of the microseismicity along the submerged section of the North Anatolian fault (NAF) within the western Sea of Marmara (SoM). The nonlinear probabilistic software packages of NonLinLoc and NLDiffLoc were used for locating earthquakes. Only earthquakes that comply with the following location criteria (e.g., representing 20% of the total amount of events) were considered for analysis: (1) number of stations≥5; (2) number of phases≥6, including both P and S; (3) root mean square (rms) location error≤0.5 s; and... |
Tipo: Text |
|
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00453/56416/58103.pdf |
| |
|
|
Batsi, Evangelia; Tsang‐hin‐sun, Eve; Klingelhoefer, Frauke; Bayrakci, Gaye; Chang, Emmy T.y.; Lin, Jing‐yi; Dellong, David; Monteil, Clément; Géli, Louis. |
Ocean bottom seismometers (OBS) commonly record short duration events (SDEs), that could be described by all of these characteristics: (i) duration < 1 s, (ii) one single‐wave train with no identified P‐ nor S‐wave arrivals and (iii) a dominant frequency usually between 4 Hz and 30 Hz. In many areas, SDEs have been associated with gas or fluid‐related processes near cold seeps or hydrothermal vents, although fish bumps, instrumental or current‐generated noise have been proposed as possible sources. In order to address some remaining issues, this study presents results from in situ and laboratory experiments combined with observations from 2 contrasting areas, the Sea of Marmara (Turkey) and the Chilean subduction zone. The in situ experiment was... |
Tipo: Text |
Palavras-chave: Marine seismology; Gas and fluid migration; Sea of Marmara; Chilean subduction. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00507/61895/65983.pdf |
| |
|
| |
|
|
Gay, Aurelien; Padron Mora, Crelia; Meyer, Solene; Beaufort, Daniel; Oliot, Emilien; Lallemand, Serge E; Marcaillou, Boris; Philippon, Mélody; Cornée, Jean-jacques; Audemard, Franck A; Lebrun, Jean-frédéric; Klingelhoefer, Frauke; Mercier De Lepinay, Bernard; Munch, Philippe; Garrocq, Clément; Boucart, Milton; Laigle, Mireille; Schenini, Laure; The Garanti Cruise Team,. |
Based on an extensive seismic and multibeam dataset, 1-5 km wide giant polygons were identified at the bottom of the Grenada basin, covering a total area of ~55000 km². They represent the top part of an active underlying polygonal fault system due to the volumetric contraction of clay- and smectite-rich sediments during burial. To date, this is the widest area of outcropping polygonal faults ever found on Earth. The seabed polygons are bounded by rectilinear ~1000-1500 m wide and ~10-60 m deep furrows, depending on the location in the basin. They are relatively regular in the north Grenada Basin, whereas they are getting longer and more elongated in the south Grenada Basin. The polygonal faults consist in a set of discrete normal faults affecting... |
Tipo: Text |
|
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00688/79963/82891.pdf |
| |
|
|
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 |
| |
|
|
De Lepinay, Bernard Mercier; Deschamps, Anne; Klingelhoefer, Frauke; Mazabraud, Yves; Delouis, Bertrand; Clouard, Valerie; Hello, Yann; Crozon, Jacques; Marcaillou, Boris; Graindorge, David; Vallee, Martin; Perrot, Julie; Bouin, Marie-paule; Saurel, Jean-marie; Charvis, Philippe; St-louis, Mildor. |
After the January 12, 2010, Haiti earthquake, we deployed a mainly offshore temporary network of seismologic stations around the damaged area. The distribution of the recorded aftershocks, together with morphotectonic observations and mainshock analysis, allow us to constrain a complex fault pattern in the area. Almost all of the aftershocks have a N-S compressive mechanism, and not the expected left-lateral strike-slip mechanism. A first-order slip model of the mainshock shows a N264 degrees E north-dipping plane, with a major left-lateral component and a strong reverse component. As the aftershock distribution is sub-parallel and close to the Enriquillo fault, we assume that although the cause of the catastrophe was not a rupture along the Enriquillo... |
Tipo: Text |
|
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00054/16557/14071.pdf |
| |
|
|
Klingelhoefer, Frauke; Gutscher, M. -a.; Ladage, S.; Dessa, J. -x.; Graindorge, D.; Franke, D.; Andre, Camille; Permana, H.; Yudistira, T.; Chauhan, A.. |
The 26 December 2004 Sumatra earthquake (M-w = 9.1) initiated around 30 km depth and ruptured 1300 km of the Indo-Australian-Sunda plate boundary. During the Sumatra-OBS (ocean bottom seismometer) survey, a wide-angle seismic profile was acquired across the epicentral region. A seismic velocity model was obtained from combined travel time tomography and forward modeling. Together with reflection seismic data from the SeaCause II cruise, the deep structure of the source region of the great earthquake is revealed. Four to five kilometers of sediments overlie the oceanic crust at the trench, and the subducting slab can be imaged down to a depth of 35 km. We find a crystalline backstop 120 km from the trench axis, below the fore-arc basin. A high-velocity zone... |
Tipo: Text |
Palavras-chave: Middle america trench; Fore arc basin; Bottom seismographic observation; Subduction zone; Crustal structure; Accretionary prism; Mantle serpentinization; Aftershock distribution; Megathrust earthquakes; Velocity structure. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00000/11155/7737.pdf |
| |
|
|
Klingelhoefer, Frauke; Lafoy, Y; Collot, Julien; Cosquer, Emmanuel; Geli, Louis; Nouze, Herve; Vially, R. |
[1] During the Zoneco 11 marine geophysical survey (September 2004), two deep reflection seismic profiles recorded by ocean bottom seismometers were acquired in the offshore domain west of New Caledonia. The northern profile crosses the New Caledonia Basin, the Fairway Ridge, the Fairway Basin, and the Lord Howe Rise. The southern profile crosses the Norfolk Rise south of New Caledonia, the New Caledonia Basin, the Fairway Ridge and Basin, and ends at the foot of Lord Howe Rise. On the northern profile the Lord Howe Rise has a crustal thickness of 23 km and exhibits seismic velocities and velocity gradients characteristic of continental crust. The crust thins to 12-15 km in the neighboring Fairway Basin, which is interpreted to be of thinned continental... |
Tipo: Text |
Palavras-chave: Crustal structure; SW Pacific; Wide angle seismic. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3543.pdf |
| |
|
| |
|
|
Klingelhoefer, Frauke; Biari, Youssef; Sahabi, Mohamed; Aslanian, Daniel; Schnabel, Michael; Matias, Luis; Benabdellouahed, Massinissa; Funck, Thomas; Gutscher, Marc-andre; Reichert, Christian; Austin, James A.. |
Deep seismic data represent a key to understand the geometry and mechanism of continental rifting. The passive continental margin of NW-Africa is one of the oldest on earth, formed during the Upper Triassic–Lower Liassic rifting of the central Atlantic Ocean over 200 Ma. We present new and existing wide-angle and reflection seismic data from four study regions along the margin located in the south offshore DAKHLA, on the central continental margin offshore Safi, in the northern Moroccan salt basin, and in the Gulf of Cadiz. The thickness of unthinned continental crust decreases from 36 km in the North to about 27 km in the South. Crustal thinning takes place over a region of 150 km in the north and only 70 km in the south. The North Moroccan Basin is... |
Tipo: Text |
Palavras-chave: Moroccan continental margin; Wide-angle seismic; Passive margins; Deep structure; Plate reconstruction. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00316/42685/42058.pdf |
| |
|
|
Gutscher, Marc-andre; Royer, Jean-yves; Graindorge, David; Murphy, Shane; Klingelhoefer, Frauke; Aiken, Chastity; Cattaneo, Antonio; Barreca, Giovanni; Quetel, Lionel; Riccobene, Giorgio; Petersen, Florian; Urlaub, Morelia; Krastel, Sebastian; Gross, Felix; Kopp, Heidrun; Margheriti, Lucia; Beranzoli, Laura. |
Laser reflectometry (BOTDR), commonly used for structural health monitoring (bridges, dams, etc.), will for the first time be applied to study movements of an active fault on the seafloor 25 km offshore Catania Sicily. The goal of the European funded FOCUS project (ERC Advanced Grant) is to connect a 6-km long strain cable to the EMSO seafloor observatory in 2100 m water depth. Laser observations will be calibrated by seafloor geodetic instruments and seismological stations. A long-term goal is the development of dual-use telecom cables with industry partners. |
Tipo: Text |
|
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00493/60430/63872.pdf |
| |
|
|
Laurencin, Muriel; Marcaillou, B.; Graindorge, D.; Klingelhoefer, Frauke; Lallemand, S.; Laigle, M.; Lebrun, J. -f.. |
The influence of the highly oblique plate convergence at the northern Lesser Antilles onto the margin strain partitioning and deformation pattern, although frequently invoked, has never been clearly imaged. The Anegada Passage is a set of basins and deep valleys, regularly related to the southern boundary of the Puerto-Rico-Virgin-Islands (PRVI) microplate. Despite the publications of various tectonic models mostly based on bathymetric data, the tectonic origin and deformation of this Passage remains unconstrained in the absence of deep structure imaging. During cruises Antithesis 1 and 3 (2013 - 2016), we recorded the first deep multichannel seismic images and new multibeam data in the northern Lesser Antilles margin segment in order to shed a new light... |
Tipo: Text |
Palavras-chave: Oblique subduction zone; Strain partitioning; Anegada Passage; Lesser Antilles margin; Multichannel seismic reflection. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00386/49710/50236.pdf |
| |
|
|
Laurencin, M.; Marcaillou, B.; Graindorge, David; Lebrun, J.‐f.; Klingelhoefer, Frauke; Boucard, M.; Laigle, M.; Lallemand, S.; Schenini, L.. |
Strain partitioning related to oblique plate convergence has long been debated in Northern Lesser Antilles. Geophysical data acquired during the ANTITHESIS cruises highlight that the sinistral strike‐slip Bunce Fault develops along the vertical, long, and linear discontinuity between the sedimentary wedge and a more rigid backstop. The narrowness of the 20‐ to 30‐km‐wide accretionary wedge and its continuity over ~850 km is remarkable. The Bunce Fault extends as far south as 18.5°N where it anastomoses within the accretionary prism where the sharp increase in convergence obliquity possibly acts as a mechanical threshold. Surface traces related to subducting seamounts suggest that 80% of the lateral component of the convergent motion is taken up by internal... |
Tipo: Text |
|
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00511/62291/66526.pdf |
| |
|
|
Moulin, Maryline; Klingelhoefer, Frauke; Afilhado, Alexandra; Aslanian, Daniel; Schnurle, Philippe; Nouze, Herve; Rabineau, Marina; Beslier, Marie-odile; Feld, Aurelie. |
The conjugate margins system of the Gulf of Lion and West Sardinia (GLWS) represents a unique natural laboratory for addressing fundamental questions about rifting due to its landlocked situation, its youth, its thick sedimentary layers, including prominent palaeo-marker such as the MSC event, and the amount of available data and multidisciplinary studies. The main goals of the SARDINIA experiment, were to (i) investigate the deep structure of the entire system within the two conjugate margins: the Gulf of Lion and West Sardinia, (ii) characterize the nature of the crust, and (iii) define the geometry of the basin and provide important constrains on its genesis. This paper presents the results of P-wave velocity modelling on three coincident near-vertical... |
Tipo: Text |
Palavras-chave: Marge continentale passive; Structure crustale; Réfraction; Golfe du Lion; Croûte océanique; Domaine transitionnel; Continental passive margin; Crustal structure; Wide-angle seismic; Gulf of Lion; Oceanic crust; Transitional domain. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00283/39422/38269.pdf |
| |
|
|
Chauhan, Ajay P. S.; Singh, Satish C.; Hananto, Nugroho D.; Carton, Helene; Klingelhoefer, Frauke; Dessa, J. -x.; Permana, H.; White, N. J.; Graindorge, D.. |
Forearc tectonics at accretionary convergent margins has variously been studied using analogue and numerical modelling techniques. Numerous geophysical investigations have targeted the subsurface structure of active forearc settings at convergent margins. However, several critical details of the structure, mode of tectonic evolution and the role forearcs play in the subduction seismic cycle remain to be further understood, especially for large accretionary margins. In this study, we present a high-resolution deep seismic reflection image of the northern Sumatran subduction forearc, near the 2004 December 26 Sumatra earthquake epicentral region. The profile clearly demarcates the backthrust branches at the seaward edge of the Aceh forearc basin, along which... |
Tipo: Text |
Palavras-chave: Forearc backthrusting; Seismic reflection image; Seismic tomography; Subduction zone processes. |
Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00000/11120/7720.pdf |
| |
|
|
Aiken, Chastity; Wessels, Richard; Cormier, Marie-hélène; Klingelhoefer, Frauke; Battani, Anne; Rolandone, Frédérique; Roest, Walter; Boisson, Dominique; Guerrier, Kelly; Momplaisir, Roberte; Ellouz-zimmerman, Nadine. |
The Haiti region – bounded by two strike-slip faults expressed both onshore and offshore – offers a unique opportunity for an amphibious drilling project. The east–west (EW)-striking, left lateral strike-slip Oriente–Septentrional fault zone and Enriquillo–Plantain Garden fault zone bounding Haiti have similar slip rates and also define the northern and southern boundaries of the Gonâve Microplate. However, it remains unclear how these fault systems terminate at the eastern boundary of that microplate. From a plate tectonic perspective, the Enriquillo–Plantain Garden fault zone can be expected to act as an inactive fracture zone bounding the Cayman spreading system, but, surprisingly, this fault has been quite active during the last 500 years. Overall,... |
Tipo: Text |
|
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00662/77402/79042.pdf |
| |
|
|
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 |
|
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00439/55072/56500.pdf |
| |
Registros recuperados: 60 | |
|
|
|