http://hdl.handle.net/2122/151 Thu, 23 May 2013 04:20:29 GMT 2013-05-23T04:20:29Z http://hdl.handle.net/2122/8686 Title: New insights from seismic tomography on the complex geodynamic evolution of two adjacent domains: Gulf of Cadiz and Alboran Sea Authors: Monna, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Cimini, G. B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Montuori, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Matias, L.; Centro de Geofísica, Universidade de Lisboa, Lisbon, Portugal.; Geissler, W. H.; Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven, Germany.; Favali, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: In this study, we present a three-dimensional P wave upper-mantle tomography model of the southwest Iberian margin and Alboran Sea based on teleseismic arrival times recorded by Iberian and Moroccan land stations and by a seafloor network deployed for 1 year in the Gulf of Cadiz area during the European Commission Integrated observations from NEAR shore sourcES of Tsunamis: towards an early warning system (EC NEAREST) project. The three-dimensional model was computed down to 600 kmdepth. The tomographic images exhibit significant velocity contrasts, as large as 3%, confirming the complex evolution of this plate boundary region. Prominent high-velocity anomalies are found beneath Betics-Alboran Sea, off-shore southwest Portugal, and north Portugal, at sublithospheric depths. The transition zones between high- and low-velocity anomalies in southwest and south Iberia are associated to the contact of oceanic and continental lithosphere. The fast structure below the Alboran Sea-Granada area depicts an L-shaped body steeply dipping from the uppermost mantle to the transition zone where it becomes less curved. This anomaly is consistent with the results of previous tomographic investigations and recent geophysical data such as stress distribution, GPS measurements of plate motion, and anisotropy patterns. In the Atlantic domain, under the Horseshoe Abyssal Plain, the main feature is a high-velocity zone found at uppermost mantle depths. This feature appears laterally separated from the positive anomaly recovered in the Alboran domain by the interposition of low-velocity zones which characterize the lithosphere beneath the southwest Iberian peninsula margin, suggesting that there is no continuity between the high-velocity anomalies of the two domains west and east of the Gibraltar Strait. Mon, 31 Dec 2012 23:00:00 GMT http://hdl.handle.net/2122/8686 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8665 Title: The Deep Sea and Sub-Seafloor Frontier Authors: Kopf, A.; MARUM, Univ. Bremen Leobener Strasse 28359 Bremen, Germany; Camerlenghi, A.; Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Trieste; Canals, M.; Departament d’Estratigrafia, Paleontologia i Geociències Marines de la Facultat de Geologia de la Universitat de Barcelona; Ferdelman, T.; Department of Biogeochemistry at the Max-Plank-Institute for Marine Microbiology, University of Bremen; Mevel, C.; Institut de Physique du Globe de Paris; Pälike, H.; The National Oceanography Centre, University of Southampton; Roest, W.; Unitè Gèosciences Marines Laboratoire Gèophysique et Gèodynamique Centre Bretagne - ZI de la Pointe du Diable - CS 10070 - 29280 Plouzané; Ask, M.; Rock Mechanics and Mining Engineering, 2006, Luleå University of Technology, Sweden; Barker-Jørgensen, B.; MPI for Marine Microbiology Celsiusstr. 1 D-28359 Bremen Germany; Boetius, A.; HGF-MPG Group for Deep Sea Ecology and Technology, Max Planck Institute for Marine Microbiology Celsiusstr. 1, 28359 Bremen, Germany; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Früh-Green, G.; Inst. f. Geochemie und Petrologie, NW E 76.2, Clausiusstrasse 25, 8092 Zuerich Abstract: The deep sea and its sub-seafloor contain a vast reservoir of physical, mineral and biological resources that are rapidly coming into the window of exploitation. Assessing the opportunities and the risks involved requires a serious commitment to excellent deep sea research. There are numerous areas in this field in which Europe has cutting-edge technological potential. These include drilling and monitoring technology in the field of renewable energies such as geothermal, offshore wind and seafloor resources. Scientific ocean drilling will continue to play a valuable role, for example in the exploration of resource opportunities, in obtaining estimates for ecosystem and Earth climate sensitivity, or in improving understanding about the controlling factors governing processes and recurrence intervals of submarine geohazards. In Europe, there is also the scientific expertise needed to define a framework for policymakers for environmental protection measures and to carry out ecological impact assessments before, during and after commercial exploitation. Taking up these societal challenges will strengthen European scientific and educational networks and promote the development of world-class technology and industrial leadership. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8665 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8663 Title: Integrating geologic fault data into tsunami hazard studies Authors: Basili, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Tiberti, M. M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Kastelic, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Romano, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Piatanesi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Selva, J.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Lorito, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Abstract: We present the realization of a fault-source data set designed to become the starting point in regional-scale tsunami hazard studies. Our approach focuses on the parametric fault characterization in terms of geometry, kinematics, and assessment of activity rates, and includes a systematic classification in six justification levels of epistemic uncertainty related with the existence and behaviour of fault sources. We set up a case study in the central Mediterranean Sea, an area at the intersection of the European, African, and Aegean plates, characterized by a complex and debated tectonic structure and where several tsunamis occurred in the past. Using tsunami scenarios of maximum wave height due to crustal earthquakes (Mw=7) and subduction earthquakes (Mw=7 and Mw=8), we illustrate first-order consequences of critical choices in addressing the seismogenic and tsunamigenic potentials of fault sources. Although tsunamis generated by Mw=8 earthquakes predictably affect the entire basin, the impact of tsunamis generated by Mw=7 earthquakes on either crustal or subduction fault sources can still be strong at many locales. Such scenarios show how the relative location/orientation of faults with respect to target coastlines coupled with bathymetric features suggest avoiding the preselection of fault sources without addressing their possible impact onto hazard analysis results. Thu, 18 Apr 2013 22:00:00 GMT http://hdl.handle.net/2122/8663 2013-04-18T22:00:00Z http://hdl.handle.net/2122/8644 Title: Eddy diffusivity derived from drifter data for dispersion model applications Authors: De Dominicis, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Leuzzi, G.; DICEA,“La Sapienza” University of Rome, Rome, Italy; Monti, P.; DICEA,“La Sapienza” University of Rome, Rome, Italy; Pinardi, N.; Corso di Scienze Ambientali, University of Bologna, Ravenna, Italy; Poulain, P.; OGS, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy Abstract: Ocean transport and dispersion processes are at the present time simulated using Lagrangian stochastic models coupled with Eulerian circulation models that are supplying analyses and forecasts of the ocean currents at unprecedented time and space resolution. Using the Lagrangian approach, each particle displacement is described by an average motion and a fluctuating part. The first one represents the advection associated with the Eulerian current field of the circulation models while the second one describes the sub-grid scale diffusion. The focus of this study is to quantify the sub-grid scale diffusion of the Lagrangian models written in terms of a horizontal eddy diffusivity. Using a large database of drifters released in different regions of the Mediterranean Sea, the Lagrangian sub-grid scale diffusion has been computed, by considering different regimes when averaging statistical quantities. In addition, the real drifters have been simulated using a trajectory model forced by OGCM currents, focusing on how the Lagrangian properties are reproduced by the simulated trajectories. Fri, 17 Aug 2012 22:00:00 GMT http://hdl.handle.net/2122/8644 2012-08-17T22:00:00Z http://hdl.handle.net/2122/8643 Title: Predictions for oil slicks detected from satellite images using MyOcean forecasting data Authors: Zodiatis, G.; Oceanography Centre, University of Cyprus, Nicosia, Cyprus; Lardner, R.; Oceanography Centre, University of Cyprus, Nicosia, Cyprus; Solovyov, D.; Oceanography Centre, University of Cyprus, Nicosia, Cyprus; Panayidou, X.; Oceanography Centre, University of Cyprus, Nicosia, Cyprus; De Dominicis, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: The pan-European capacity for the Ocean Monitoring and Forecasting (MyOcean) Marine Core Service, implementing the Global Monitoring for Environment and Security (GMES) objectives, targets the provision of ocean state observations from various platforms and analysis and forecasting products to assist, among other downscaling activities, the needs of the operational response to marine safety, particularly concerning oil spills. The MEDSLIK oil spill and trajectory prediction system makes use of the MyOcean regional and Cyprus Coastal Ocean Forecasting and Observing System (CYCOFOS) downscaled forecasting products for operational application in the Mediterranean and pre-operational use in the Black Sea. Advanced Synthetic Aperture Radar (ASAR) satellite remote sensing images from the European Space Agency (ESA) and European Maritime Safety Agency CleanSeaNet (EMSA-CSN) provide the means for routine monitoring of the southern European seas for the detection of illegal oil discharges. MEDSLIK offers various ways, to be described in this paper, of coupling the MyOcean forecasting data with ASAR images to provide both forecasts and hindcasts for such remotely observed oil slicks. The main concern will be the drift of the oil slick and also, in the case of the forecast mode, its diffusive spreading, although some attempt is also made to estimate the changes in the state of the oil. The successful link of the satellite-detected oil slicks with their operational predictions using the MyOcean products contributes to the operational response chain and the strengthening of maritime safety for accidental or illegal spills, in implementation of the Mediterranean Decision Support System for Marine Safety (MEDESS-4MS) regarding oil spills. Mon, 17 Dec 2012 23:00:00 GMT http://hdl.handle.net/2122/8643 2012-12-17T23:00:00Z http://hdl.handle.net/2122/8588 Title: Predictability of the mid-latitude Atlantic meridional overturning circulation in a multi-model system Authors: Pohlmann, H.; Max-Planck-Institut fu ̈r Meteorologie,; Smith, D. M.; Met Office Hadley Centre; Balmaseda, M. A.; ECMWF; Keenlyside, N. S.; Geophysical Institute and Bjerknes Centre, University of Bergen; Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Matei, D.; Max-Planck-Institut fu ̈r Meteorologie,; Muller, W. A.; Max-Planck-Institut fu ̈r Meteorologie,; Rogel, P.; CERFACS Abstract: Assessing the skill of the Atlantic meridional overturning circulation (AMOC) in decadal hindcasts (i.e. retrospective predictions) is hampered by a lack of obser- vations for verification. Models are therefore needed to reconstruct the historical AMOC variability. Here we show that ten recent oceanic syntheses provide a common signal of AMOC variability at 45°N, with an increase from the 1960s to the mid-1990s and a decrease thereafter although they disagree on the exact magnitude. This signal corre- lates with observed key processes such as the North Atlantic Oscillation, sub-polar gyre strength, Atlantic sea surface temperature dipole, and Labrador Sea convection that are thought to be related to the AMOC. Furthermore, we find potential predictability of the mid-latitude AMOC for the first 3–6 year means when we validate decadal hindcasts for the past 50 years against the multi-model signal. However, this predictability is not found in models driven only by external radiative changes, demonstrating the need for initialization of decadal climate predictions. Mon, 31 Dec 2012 23:00:00 GMT http://hdl.handle.net/2122/8588 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8587 Title: Ensemble spread-based assessment of observation impact: Application to a global ocean analysis system Authors: Storto, A.; CMCC; Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Dobricic, S.; CMCC Abstract: This article explores an ensemble strategy for evaluating the impact of different observing networks. The impact is represented by the relative ensemble spread increase, in model space, of data-denial ensemble simulations with respect to an ‘all-observation’ ensemble experiment, evaluated independently for each observing network. The forecast-error covariance intercomparison reduces to the ensemble spread intercomparison; thus, the method can be applied to any assimilation system and requires only the proper construction of an ensemble system, although the impact assessment results depend on the specific configuration of the investigated analysis system. Our approach allows us to determine the impact of the observing networks in model space (unlike Observing System Experiments) and for different forecast ranges of the ocean general circulation model. No tangent-linear and adjoint coding of the ocean model are required. The method is applied for demonstration to a large-scale global ocean variational analysis system. The ensemble members are generated by (i) perturbing the observations within the 3D-Var assimilation scheme, (ii) perturbing the surface forcing, and (iii) stochastically perturbing the ocean model parametrisation tendencies. The impact is calculated for CTDs, XBTs, moorings, Argo, sea-level anomaly observations and sea-surface temperature measurements from space-borne microwave instruments within the three-year period from January 2003 to December 2005. It turns out, on the global scale, that altimetry exhibits the largest impact on near-surface temperature and sea-surface height. In contrast, deep-ocean impacts are led by the Argo float network. As expected, space-borne observations (sea-level anomaly and sea-surface temperature observations) increase their impact in the Southern Ocean, due to the lack of a robust network of in situ observations. The results of the impact on the salinity indicate the great importance of Argo floats, especially in the northern Extratropics. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8587 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8501 Title: Mazara del Vallo tide gauge observations (1906-1916): land subsidence or sea level rise? Authors: Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Spada, G.; Dipartimento di Scienze di Base e Fondamenti, Urbino University “Carlo Bo”; Antonioli, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Galassi, G.; Dipartimento di Scienze di Base e Fondamenti, Urbino University “Carlo Bo” Abstract: Tide gauge data constitute an invaluable tool for the interpretation of short and long-term sea level changes occurring in the Mediterranean Sea. The complex geophysical environment and the limited amount of sufficiently long records make the interpretation of local signals problematic, since these are often affected by interlacing processes. Starting from newly disclosed tide gauge records from the site of Mazara del Vallo (SW Sicily), we analyze simultaneously the time series available from other locations in Sicily across the beginning of the 20th century (Messina and Palermo). Despite the limited record length, we show that these observations provide new perspectives on the causes of the observed sea level variations in the central Mediterranean region, and in particular they challenge previous tenets regarding the extent of land movements caused by the 1908 Messina Straits earthquake. Mon, 31 Dec 2012 23:00:00 GMT http://hdl.handle.net/2122/8501 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8469 Title: Orbital variations in planktonic foraminifera assemblages from the Ionian Sea during the Middle Pleistocene Transition Authors: Incarbona, A.; Università degli Studi di Palermo, Dipartimento di Scienze della Terra e del Mare, Via Archirafi 22, 90134 Palermo, Italy; Dinarès-Turell, J.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Di Stefano, E.; Università degli Studi di Palermo, Dipartimento di Scienze della Terra e del Mare, Via Archirafi 22, 90134 Palermo, Italy; Ippolito, G.; Università degli Studi di Palermo, Dipartimento di Scienze della Terra e del Mare, Via Archirafi 22, 90134 Palermo, Italy; Pelosi, N.; Consiglio Nazionale delle Ricerche, Istituto per l'Ambiente Marino Costiero, Calata Porto di Massa, Interno Porto di Napoli, 80133, Naples, Italy; Sprovieri, R.; Università degli Studi di Palermo, Dipartimento di Scienze della Terra e del Mare, Via Archirafi 22, 90134 Palermo, Italy Abstract: The Middle Pleistocene Transition (1.2-0.7 Ma) is the most recent re-organization of the global climate system which includes variations in the frequency and amplitude of glacial/interglacial cycles, increased ice sheet volume, sea surface temperature cooling and a significant drop in the CO2 atmospheric levels. Here we present high-resolution planktonic foraminifera data (mean sampling resolution of about 780 years) from core LC10 recovered in the Ionian Sea (eastern Mediterranean), between 1.2 and 0.9 Ma. Selected taxa, among them G. ruber, T. quinqueloba and G. bulloides, show significant periodicities that can be associated to orbital cycles, mainly precession and obliquity. The planktonic foraminifera based paleoclimatic curve exhibits a cooling linear trend that can be associated to similar phenomena observed in the North Atlantic. On the other hand, we refer to the influence of the North African Monsoon the occurrence of two peaks of the low-salinity tolerant species G. quadrilobatus that fall in coincidence of sapropel layers. Finally, we discuss the distribution pattern of N. pachyderma sinistral coiling, with peaks up to about 20% between MIS 30 and 28, and compare it to middle-late Quaternary records of the Sicily Channel and western Mediterranean. Mon, 31 Dec 2012 23:00:00 GMT http://hdl.handle.net/2122/8469 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8459 Title: NEMO-SN1 (Western Ionian Sea, off Eastern Sicily): Example of architecture of a cabled observatory Authors: Favali, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Azzarone, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Badiali, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Beranzoli, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Cianchini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Qamili, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; De Caro, M.G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Doumaz, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Embriaco, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Falcone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Giovanetti, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Lo Bue, N.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Marinaro, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Monna, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Montuori, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Sgroi, T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Vinci, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; NEMO Collaboration, NEMO Collaboration; INFN - Istituto Nazionale di Fisica Nucleare (INFN), Italy; Chierici, F.; CNR-ISMAR - Consiglio Nazionale delle Ricerche, Istituto delle Scienze Marine; Pignagnoli, L.; CNR-ISMAR - Consiglio Nazionale delle Ricerche, Istituto delle Scienze Marine; Zitellini, N.; CNR-ISMAR - Consiglio Nazionale delle Ricerche, Istituto delle Scienze Marine; Bruni, F.; Tecnomare S.p.A, Italy; Gasparoni, F.; Tecnomare S.p.A, Italy Abstract: NEMO-SN1, located in the central Mediterranean Sea, Western Ionian Sea, off Eastern Sicily Island (Southern Italy) at 2100 m water depth, 25 km from the harbour of the city of Catania, is a prototype of a cabled deep-sea multiparameter observatory and the first operating with real-time data transmission in Europe since 2005. NEMO-SN1 is also the first-established node of EMSO (European Multidisciplinary Seafloor Observatory, http://emso-eu.org), one of the incoming European large-scale research infrastructure included since 2006 in the Roadmap of the ESFRI (European Strategy Forum on Research Infrastructures, http://cordis.europa.eu/esfri/roadmap.htm), which will specifically address long-term monitoring of environmental processes related to Marine Ecosystems, Climate Change and Geo-hazards. NEMO-SN1 has been deployed and developed over the last decade thanks to Italian resources and to the EC project ESONET-NoE (European Seas Observatory NETwork - Network of Excellence, 2007-2011) that funded the LIDO-DM (Listening to the Deep Ocean - Demonstration Mission) and a technological interoperability test (http://www.esonet-emso.org/esonet-noe/). NEMO-SN1 is performing geophysical and environmental long-term monitoring by acquiring seismological, geomagnetic, gravimetric, accelerometric, physico-oceanographic, hydro-acoustic, bioacoustic measurements specifically related to earthquakes and tsunamis generation and ambient noise characterisation in term of marine mammal sounds, environmental and anthropogenic sources. A further main feature of NEMO-SN1 is to be an important test-site for the construction of KM3NeT (Kilometre-Cube Underwater Neutrino Telescope, http://www.km3net.org/), another large-scale research infrastructure included in the ESFRI Roadmap constituted by a large volume neutrino telescope. The description of the observatory and the most recent data acquired will be presented and framed in the general objectives of EMSO. Mon, 04 Apr 2011 22:00:00 GMT http://hdl.handle.net/2122/8459 2011-04-04T22:00:00Z