ALBERT

Beschreibung:    A detailed reconstruction of the stratigraphic and tectonic setting of the Gulf of Pozzuoli (Naples Bay) is provided on the basis of newly acquired single channel seismic profiles coupled with already recorded marine magnetics gathering the volcanic nature of some seismic units. Inferences for the tectonic and magmatic setting of the Phlegrean Fields volcanic complex, a volcanic district surrounding the western part of the Gulf of Naples, where volcanism has been active since at least 50 ka, are also discussed. The Gulf of Pozzuoli represents the submerged border of the Phlegrean caldera, resulting from the volcano-tectonic collapse induced from the pyroclastic flow deposits of the Campanian Ignimbrite (35 ka). Several morpho-depositional units have been identified, i.e., the inner continental shelf, the central basin, the submerged volcanic banks and the outer continental shelf. The stratigraphic relationships between the Quaternary volcanic units related to the offshore caldera border and the overlying deposits of the Late Quaternary depositional sequence in the Gulf of Pozzuoli have been highlighted. Fourteen main seismic units, both volcanic and sedimentary, tectonically controlled due to contemporaneous folding and normal faulting have been revealed by geological interpretation. Volcanic dykes, characterized by acoustically transparent sub-vertical bodies, locally bounded by normal faults, testify to the magma uprising in correspondence with extensional structures. A large field of tuff cones interlayered with marine deposits off the island of Nisida, on the western rim of the gulf, is related to the emplacement of the Neapolitan Yellow Tuff deposits. A thick volcanic unit, exposed over a large area off the Capo Miseno volcanic edifice is connected with the Bacoli-Isola Pennata-Capo Miseno yellow tuffs, cropping out in the northern Phlegrean Fields. Content Type Journal Article Category Original Research Paper Pages 1-29 DOI 10.1007/s11001-012-9150-8 Authors Gemma Aiello, Institute of Marine, Environment and Coastal Area (IAMC), National Research Council (CNR), Calata Porta di Massa, Porto di Napoli, 80133 Naples, Italy Ennio Marsella, Institute of Marine, Environment and Coastal Area (IAMC), National Research Council (CNR), Calata Porta di Massa, Porto di Napoli, 80133 Naples, Italy Vincenzo Di Fiore, Institute of Marine, Environment and Coastal Area (IAMC), National Research Council (CNR), Calata Porta di Massa, Porto di Napoli, 80133 Naples, Italy Journal Marine Geophysical Research Online ISSN 1573-0581 Print ISSN 0025-3235

Beschreibung:    Information theory and fractal analysis are the basis of a novel fitting criterion for simultaneous plate tectonic reconstructions of magnetic isochrons and fracture zone crossings of a range of ages, rather than a single isochron age. Accretionary boundaries are modeled as two-dimensional fractal structures including both contemporary spreading boundaries and reconstructed magnetic isochron and fracture zone crossings. Each model incorporates reconstruction parameters which describe the full accretionary history, including asymmetry. The reconstruction parameters are derived by spline interpolation in time of trial rotation pseudovectors, including variable asymmetric spreading between ridge segments. Iterative algorithms, without partial derivative constraints, converge on a nominally optimal model by minimizing the sum of two-dimensional fractal bins, over the range of bin-spacings, and produce thereby progressively refined fractal spectra. The new method can incorporate all isochron identifications from the selected plates and age range in the iterative calculation set. The solution set also provides continuous instantaneous rotation parameters, including asymmetries. An example data set illustrates the methodology and model results. The rationale for an optimal fractal criterion is rooted in recent developments in information theory: fractal structures maximize Shannon information entropy distributed over a range of scales. The fractal measure is the sum of bins occupied by reconstructed data points for each bin spacing. The fitting criterion utilized in this work is, in turn, the grand sum of the fractal measures over all calculated bin spacings. The optimal fractal measure for the grand sum has minimal integrated “fractality” relative to non-optimal sets while maximizing entropy for the optimal parameters for each bin spacing. Content Type Journal Article Category Original Research Paper Pages 1-20 DOI 10.1007/s11001-012-9152-6 Authors Rex H. Pilger Jr., 10630 W 66th Ave, Arvada, CO 80004, USA Journal Marine Geophysical Research Online ISSN 1573-0581 Print ISSN 0025-3235

Beschreibung: Editorial for MGR Content Type Journal Article Category Editorial Pages 215-216 DOI 10.1007/s11001-010-9098-5 Authors Peter Clift, Department of Geology and Petroleum Geology, King’s College, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE UK Journal Marine Geophysical Research Online ISSN 1573-0581 Print ISSN 0025-3235 Journal Volume Volume 30 Journal Issue Volume 30, Number 4

Beschreibung:    Gridding heterogeneous bathymetric data sets for the compilation of Digital bathymetric models (DBMs), poses specific problems when there are extreme variations in source data density. This requires gridding routines capable of subsampling high-resolution source data while preserving as much as possible of the small details, at the same time as interpolating in areas with sparse data without generating gridding artifacts. A frequently used gridding method generalizes bicubic spline interpolation and is known as continuous curvature splines in tension. This method is further enhanced in this article in order to specifically handle heterogeneous bathymetric source data. Our method constructs the final grid through stacking several surfaces of different resolutions, each generated using the splines in tension algorithm. With this approach, the gridding resolution is locally adjusted to the density of the source data set: Areas with high-resolution data are gridded at higher resolution than areas with sparse source data. In comparison with some of the most widely used gridding methods, our approach yields superior DBMs based on heterogeneous bathymetric data sets with regard to preserving small bathymetric details in the high-resolution source data, while minimizing interpolation artifacts in the sparsely data constrained regions. Common problems such as artifacts from ship tracklines are suppressed. Even if our stacked continuous curvature splines in tension gridding algorithm has been specifically designed to construct DBMs from heterogeneous bathymetric source data, it may be used to compile regular grids from other geoscientific measurements. Content Type Journal Article Category Original Research Paper Pages 1-9 DOI 10.1007/s11001-011-9141-1 Authors Benjamin Hell, Department of Geological Sciences, Stockholm University, 10691 Stockholm, Sweden Martin Jakobsson, Department of Geological Sciences, Stockholm University, 10691 Stockholm, Sweden Journal Marine Geophysical Research Online ISSN 1573-0581 Print ISSN 0025-3235

Beschreibung:    In this paper the main wave height characteristics in the Mediterranean Sea are studied from both observational and numerical perspectives. The numerical wave model WAM is employed on a high spatial resolution mode and in two different versions, one of which incorporates information for sea surface currents. Altimeter data obtained from all available satellite missions over the area are also utilized. The data sets are analyzed both by conventional statistical measures as well as by advanced techniques provided by a relatively new branch of mathematics, information geometry, in the framework of which the data under study and the distributions that they form are treated as elements of non Euclidean spaces. In this framework, novel ideas for the estimation of the deviations between the observed and modeled values are proposed. Content Type Journal Article Category Original Research Paper Pages 1-15 DOI 10.1007/s11001-011-9142-0 Authors George Galanis, Section of Mathematics, Hellenic Naval Academy, Xatzikyriakion, 18539 Piraeus, Greece Dan Hayes, Oceanography Centre, University of Cyprus, 1678 Nicosia, Cyprus George Zodiatis, Oceanography Centre, University of Cyprus, 1678 Nicosia, Cyprus Peter C. Chu, Department of Oceanography, Naval Postgraduate School, Graduate School of Engineering and Applied Science, Monterey, CA 93943, USA Yu-Heng Kuo, Department of Oceanography, Naval Postgraduate School, Graduate School of Engineering and Applied Science, Monterey, CA 93943, USA George Kallos, Department of Physics, Atmospheric Modeling and Weather Forecasting Group, University of Athens, University Campus, Bldg. PHYS-V, 15784 Athens, Greece Journal Marine Geophysical Research Online ISSN 1573-0581 Print ISSN 0025-3235

Beschreibung:    The subseafloor structure offshore South China Sea was imaged using first-order water-layer multiples from ocean-bottom seismometer data and the results were compared to conventional imaging using primary reflections. The mirror-imaging method employs a primaries-only reverse time pre-stack depth migration algorithm to image the receiver ghosts. The additional travel path of the multiples through the water layer is accounted for by a simple manipulation of the velocity model and processing datum: the receivers lie not on the sea floor but on a sea surface twice as high as the true water column. Migration results show that the multiple-migrated image provides a much broader illumination of the subsurface than the conventional image using the primaries, especially for the very shallow reflections. The resulting image from mirror imaging has illumination comparable to the vertical incidence surface streamer (single-channel) reflection data. Content Type Journal Article Category Original Research Paper Pages 1-7 DOI 10.1007/s11001-012-9148-2 Authors Xiangchun Wang, Key Laboratory of Geo-detection, China University of Geosciences (Beijing), Ministry of Education, Beijing, 100083 China Changliang Xia, Overseas Business Department of Geophysical Research Institute, BGP Inc. of CNPC, Zhuozhou City, 072750 Hebei Province, China Xuewei Liu, Key Laboratory of Geo-detection, China University of Geosciences (Beijing), Ministry of Education, Beijing, 100083 China Journal Marine Geophysical Research Online ISSN 1573-0581 Print ISSN 0025-3235

Beschreibung:    Recent developments in seafloor imaging and mapping techniques greatly improved our capability of identifying marine geohazards affecting continental margins. Geomorphic features can be detected in great detail by high-resolution multibeam imaging and regarded as geohazard indicators; the most common include slide scars and deposits, canyon headscarps and steep erosional flanks, fault-related seafloor unevenness, mud volcanoes, pockmarks, gravity flow deposits, erosional scours and bedforms indicating sediment mobility at diverse temporal/spatial scale. These processes are widespread on Italian continental margins and are potential indicators of geohazard for human settlements and infrastructures in the offshore and coastal zones. The national Project MaGIC (Marine Geohazards along the Italian Coasts) aims at documenting potential geohazards based on the acquisition of high-resolution multibeam bathymetry and on the production of maps of the geohazard-related geomorphic features for most of the Italian continental margins. With reference to this issue, we discuss some of the most frequent problems dealing with reconnaissance, interpretation and cartographic representation of geohazard-related geomorphic features at a regional scale. Content Type Journal Article Pages 1-11 DOI 10.1007/s11001-011-9120-6 Authors Francesco L. Chiocci, Dipartimento di Scienze della Terra, Universita La Sapienza, Rome, Italy Domenico Ridente, Istituto di Geologia Ambientale e Geoingegneria (IGAG)-CNR, Rome, Italy Journal Marine Geophysical Research Online ISSN 1573-0581 Print ISSN 0025-3235

Beschreibung:    Based on new multibeam bathymetric data, seismic-reflection profiles and side-scan sonar images, a great number of submarine failures of various types and sizes was identified along the northern margin of the Ligurian Basin and characterized with 3 distinct end-members concerning their location on the margin, sedimentary processes and possible triggering mechanisms. They include superficial landslides mainly located in the vicinity of the main mountain-supplied rivers and on the inner walls of canyons (typically smaller that 10 8  m 3 in volume: Type 1), deep scars 100–500 m high along the base of the continental slope (Type 2), and large-scale scars and Mass Transport Deposits (MTDs) affecting the upper part of the slope (Type 3 failures). The MTDs are located in different environmental contexts of the margin, including the deep Var Sedimentary Ridge (VSR) and the upper part of the continental slope in the Gulf of Genova (Finale Slide and Portofino Slide), with volumes of missing sediment reaching up to 1.5 × 10 9  m 3 . High sedimentation rates related to hyperpycnal flows, faults and earthquake activity, together with sea-level fluctuations are the main factors invoked to explain the distribution and sizes of these different failure types. Content Type Journal Article Pages 1-19 DOI 10.1007/s11001-011-9123-3 Authors Sébastien Migeon, UMR GéoAzur, Université de Nice-Sophia Antipolis, CNRS, OCA, Port de la darse, 06235 Villefrance/Mer, France Antonio Cattaneo, IFREMER, GM-LES, 29280 Plouzané, France Virginie Hassoun, UMR GéoAzur, Université de Nice-Sophia Antipolis, CNRS, OCA, Port de la darse, 06235 Villefrance/Mer, France Christophe Larroque, UMR GéoAzur, Université de Nice-Sophia Antipolis, CNRS, OCA, 250 Rue A. Einstein, 06560 Valbonne, France Nicola Corradi, University of Genova, Dip.Te.Ris, Corso Europa, 26, 16100 Genoa, Italy Francesco Fanucci, University of Trieste, DiGe, Italy Alexandre Dano, UMR GéoAzur, Université de Nice-Sophia Antipolis, CNRS, OCA, Port de la darse, 06235 Villefrance/Mer, France Bernard Mercier de Lepinay, UMR GéoAzur, Université de Nice-Sophia Antipolis, CNRS, OCA, 250 Rue A. Einstein, 06560 Valbonne, France Françoise Sage, UMR GéoAzur, Université de Nice-Sophia Antipolis, CNRS, OCA, Port de la darse, 06235 Villefrance/Mer, France Christian Gorini, UMR iSTeP, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris cedex05, France Journal Marine Geophysical Research Online ISSN 1573-0581 Print ISSN 0025-3235

Beschreibung:    The northern East China Sea Shelf Basin consists of three depressions (the Domi, Jeju, and Socotra Depressions), separated by basement highs or rises. Reconstruction of depth-converted seismic reflection profiles from these depressions reveals that the northern East China Sea Shelf Basin experienced two phases of rifting, followed by regional subsidence. Initial rifting in the Late Cretaceous was driven by the NW–SE crustal stretching of the Eurasian plate, caused by the subduction of the Pacific plate beneath the plate margin. Major extension (~15 km) took place during the early phase of basin formation. The initial rifting was terminated by regional uplift in the Late Eocene-Early Oligocene, which was probably due to reorganization of plate boundaries. Rifting resumed in the Early Oligocene; the magnitude of extension was mild (〈1 km) during this period. A second phase of uplift in the Early Miocene terminated the rifting, marking the transition to the postrift phase of regional subsidence. Up to 2,600 m of sediments and basement rock were removed by erosion during and after the second phase of uplift. An inversion in the Late Miocene interrupted the postrift subsidence, resulting in an extensive thrust-fold belt in the eastern part of the area. Subsequent erosion removed about 900 m of sediments. The regional subsidence has dominated the area since the Late Miocene. Content Type Journal Article Pages 1-19 DOI 10.1007/s11001-011-9114-4 Authors Deniz Cukur, Leibniz Institute for Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany Senay Horozal, Department of Energy Resources Engineering, Pukyong National University, Busan, 608-737 South Korea Gwang H. Lee, Department of Energy Resources Engineering, Pukyong National University, Busan, 608-737 South Korea Dae C. Kim, Department of Energy Resources Engineering, Pukyong National University, Busan, 608-737 South Korea Hyun C. Han, Korea Institute of Geoscience and Mineral Resources, Daejon, 305-350 South Korea Moo H. Kang, Korea Institute of Geoscience and Mineral Resources, Daejon, 305-350 South Korea Journal Marine Geophysical Researches Online ISSN 1573-0581 Print ISSN 0025-3235

Beschreibung:    Interpretation of deep 2-D multi-channel seismic data sheds insights into the geological evolution of the West Luzon Basin, Philippines. This basin is a sediment-filled trough that is located between the island of Luzon and the outer arc high of the west Luzon subduction zone. High-amplitude, low-frequency reflection bands mark the acoustic basement. The basement, at about 6 s (TWT), is dissected by normal faults with some of them being inverted in a later phase of deformation. The sedimentary successions, overlying the basement are stratified with partly chaotic structures and discontinuous reflectors. Five regional unconformities separate major stratigraphic units. Grid calculations of our seismic data reveal variations in the sedimentation pattern of the basin with a shift of the deposition centre from east to west and backwards during formation. A distinct bottom-simulating reflector is commonly observed. Because the northern boundary of the continental fragments to the South of the West Luzon Basin is unclear we speculate that the basin may be (partly) underlain by continental crust. The continental crust was affected by rifting prior to and during the opening of the South China Sea and the basin was overprinted at a later stage by a forearc structural setting when subduction was initiated. Content Type Journal Article Pages 1-14 DOI 10.1007/s11001-010-9113-x Authors Jashar Arfai, Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655 Hannover, Germany Dieter Franke, Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655 Hannover, Germany Christoph Gaedicke, Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655 Hannover, Germany Rüdiger Lutz, Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655 Hannover, Germany Michael Schnabel, Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655 Hannover, Germany Stefan Ladage, Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655 Hannover, Germany Kai Berglar, Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655 Hannover, Germany Mario Aurelio, National Institute of Geological Sciences, College of Science, University of the Philippines, Velasquez St., U. P. Campus, 1101 Diliman, Quezon City, Philippines Jennie Montano, National Institute of Geological Sciences, College of Science, University of the Philippines, Velasquez St., U. P. Campus, 1101 Diliman, Quezon City, Philippines Nicole Pellejera, National Institute of Geological Sciences, College of Science, University of the Philippines, Velasquez St., U. P. Campus, 1101 Diliman, Quezon City, Philippines Journal Marine Geophysical Researches Online ISSN 1573-0581 Print ISSN 0025-3235