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Stephanie B.,ANSES French Agency for Food | Mireille C.,Ifremer French Research Institute for Exploration of the Sea
Food Quality and Preference | Year: 2014

The aim of the paper is to propose an alternative method to external preference mapping for the case of complex data where explanatory variables are organized in meaningful blocks. We propose an innovative method in the multiblock modeling framework, called multiblock Redundancy Analysis. The interest and relevance of this method is illustrated on the basis of a European consumer preference study for cold-smoked salmon. The study aims at explaining six homogeneous clusters of preference with explanatory parameters organized in five thematic blocks related to physico-chemical measurements, microbiological characterization, appearance attributes, odor/flavor characterization and texture descriptors. Overall indexes and graphical displays associated with different interpretation levels are proposed to sort the key drivers of preference by order of priority at the variables and at the block level. On the basis of these data, multiblock Redundancy Analysis is also compared to standard preference mapping in terms of model quality; the best model is here associated with the multiblock method. © 2013 Elsevier Ltd.

Arnaud-Haond S.,Ifremer French Research Institute for Exploration of the Sea | Arrieta J.M.,CSIC - Mediterranean Institute for Advanced Studies | Duarte C.M.,CSIC - Mediterranean Institute for Advanced Studies | Duarte C.M.,University of Western Australia
Science | Year: 2011

Ten countries account for 90% of patent claims associated with marine genes, including some from international waters.

Marsset B.,Ifremer French Research Institute for Exploration of the Sea | Thomas Y.,Ifremer French Research Institute for Exploration of the Sea | Sultan N.,Ifremer French Research Institute for Exploration of the Sea | Gaillot Y Stephan A.,SHOM
Near Surface Geophysics | Year: 2012

Seismic velocities together with sediment/rock compaction models are of common use in the oil industry to predict reservoir pressures and to detect and identify any potential hazard associated with over-pressured formations. Excess pore pressure is a key parameter for geohazard assessment, nevertheless this approach is very seldom applied to shallow offshore engineering as it requires expensive ground-truth boreholes. The simultaneous availability in the Bourcart-Hérault canyon interfluve (Gulf of Lion - NW Mediterranean) of 1) geotechnical and sedimentological data (300 m boreholes) from the PROMESS project; 2) in situ pore pressure measurements; and 3) High Resolution (HR) seismic geophysical data showing the presence of active structures in relation to fluid circulation, allows the importance of a multi-disciplinary approach to shallow geohazard assessment to be illustrated through a case study. The velocity field obtained from HR seismic data is interpreted in light of the neighbouring boreholes and resulting velocity anomalies are translated in terms of fluid overpressure and free gas content. Additional in situ surface geotechnical measurements (piezometers) are then taken into account and the role of these parameters is discussed. © 2012 European Association of Geoscientists & Engineers.

Steiner A.,University of Bremen | Kopf A.J.,University of Bremen | Henry P.,Aix - Marseille University | Stegmann S.,University of Bremen | And 2 more authors.
Marine Geology | Year: 2015

In the landslide-prone area near the Nice international airport, southeastern France, an interdisciplinary approach is applied to develop realistic lithological/geometrical profiles and geotechnical/strength sub-seafloor models. Such models are indispensable for slope stability assessments using limit equilibrium or finite element methods. Regression analyses, based on the undrained shear strength (su) of intact gassy sediments are used to generate a sub-seafloor strength model based on 37 short dynamic and eight long static piezocone penetration tests, and laboratory experiments on one Calypso piston and 10 gravity cores. Significant strength variations were detected when comparing measurements from the shelf and the shelf break, with a significant drop in su to 5.5kPa being interpreted as a weak zone at a depth between 6.5 and 8.5m below seafloor (mbsf). Here, a 10% reduction of the in situ total unit weight compared to the surrounding sediments is found to coincide with coarse-grained layers that turn into a weak zone and detachment plane for former and present-day gravitational, retrogressive slide events, as seen in 2D chirp profiles. The combination of high-resolution chirp profiles and comprehensive geotechnical information allows us to compute enhanced 2D finite element slope stability analysis with undrained sediment response compared to previous 2D numerical and 3D limit equilibrium assessments. Those models suggest that significant portions (detachment planes at 20m or even 55mbsf) of the Quaternary delta and slope apron deposits may be mobilized. Given that factors of safety are equal or less than 1 when further considering the effect of free gas, a high risk for a landslide event of considerable size off Nice international airport is identified. © 2015 Elsevier B.V.

Thomas Y.,Ifremer French Research Institute for Exploration of the Sea | Marsset B.,Ifremer French Research Institute for Exploration of the Sea | Westbrook G.K.,Ifremer French Research Institute for Exploration of the Sea | Grail C.,Ifremer French Research Institute for Exploration of the Sea | And 6 more authors.
Near Surface Geophysics | Year: 2012

High Resolution (HR) marine seismic acquisition contributes to numerous research fields. The vertical resolution is of metric scale in order to study geological processes at a short time scale or to characterise small objects. 3D seismic imaging allows optimal resolution to be reached whereas 2D images are blurred mainly by side effects. Developed for the oil industry decades ago and tailored to the exploration for hydrocarbon reservoirs, 3D seismic, as applied to higher resolution targets, is more recent. Available technological advances in acquisition have allowed research institutes to develop innovative 3D high-resolution marine seismic systems tailored to these targets. The seismic survey carried out in 2009 on the Western High, Sea of Marmara, illustrates the value of HR3D imaging. Since the destructive izmit earthquake in 1999, an intensive international research effort has demonstrated that the Western High is one of the key structures for assessing the processes of deformation related to the North Anatolian Fault (NAF). The 30-km 2 HR3D survey centred on the main NAF was acquired using a dual streamers - dual source-array configuration. In spite of the minimal 3D processing sequence that was applied to the data, the fine imaging of the seabed and of the sedimentary stratigraphy and structures is much better than HR2D seismic. Comparison with an autonomous underwater vehicle (AUV) multi-beam bathymetric survey carried out at the same location enables the limits of the vertical resolution of the seismic data to be assessed. The lateral resolution is between 13.5 and 25 metres at the seabed. The HR3D seismic data highlight the interplay between tectonic processes and stratigraphy. In particular, differential uplift leads to syntectonic deposition and submarine slides. The widespread occurrence of gas in the sedimentary sequence is clearly shown by anomalously high seismic amplitudes. 3D imaging of these high amplitudes enables the identification of the pathways through faults and permeable units that gas takes as it migrates to the seabed. © 2012 European Association of Geoscientists & Engineers.

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