scholarly journals Geodynamics of the Central Mediterranean (GEOMED) inferred from ambient seismic noise

2021 ◽  
Author(s):  
Matthew Agius ◽  
Fabrizio Magrini ◽  
Giovanni Diaferia ◽  
Fabio Cammarano ◽  
Claudio Faccenna ◽  
...  
Keyword(s):  
Seismic Noise ◽  
Rift Zone ◽  
Ambient Seismic Noise ◽  
Special Focus ◽  
Tyrrhenian Sea ◽  
The European Union ◽  
Central Mediterranean ◽  
Phase Velocity Dispersion ◽  
Radial Anisotropy ◽  
Sicily Channel

<p>The Central Mediterranean, the area encompassing Italy, Sardinia, Tunisia and Libya, is characterised by multiple tectonic processes (plate convergence, subduction, and backarc extension). The evolution and interaction of the plate margins within this relatively small area are still being unravelled particularly at the adjacent region known as the Sicily Channel located between Sicily, Tunisia, Libya and Malta. This Channel is characterised by a seismically and volcanically active rift zone. Much of the observations we have today for the southern parts of the Calabrian arc are either limited to the surface and the upper crust, or are broader and deeper from regional seismic tomography, missing important details about the lithospheric structure and dynamics. The project GEOMED (https://geomed-msca.eu) addresses this issue by processing all the seismic data available in the region in order to understand better the geodynamics of the Central Mediterranean.</p><p>We measure Rayleigh- and Love-wave phase velocities from ambient seismic noise recordings to infer the structures of the Central Mediterranean, from the Central Apennines to the African foreland, with a special focus on the Sicily Channel Rift Zone (SCRZ). The phase-velocity dispersion curves have periods ranging from 5 to 100 seconds and sample through the entire lithosphere. We invert the dispersion data for isotropic and polarised shear velocities with depth and infer crustal thickness and patterns of radial anisotropy. We find that continental blocks have thick crust (30-50 km), whereas beneath the SCRZ the crust is thin (<25 km), and thinner beneath the Tyrrhenian Sea. Beneath the SCRZ and the Tyrrhenian Sea, the crustal shear velocities are characterised by positive radial anisotropy (V<sub>SH</sub>>V<sub>SV</sub>) indicative of horizontal flow or extension, whereas the uppermost mantle is characterised by slow shear velocities indicative of warmer temperatures and strong negative radial anisotropy (V<sub>SH</sub>>V<sub>SV</sub>) indicative of vertical flow. We discuss the relevance of these findings together with other geophysical studies such as the regional seismicity and GPS velocity vectors to identify the rifting process type of the SCRZ.</p><p>This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 843696.</p>

scholarly journals Numerical simulation and decomposition of kinetic energy in the Central Mediterranean: insight on mesoscale circulation and energy conversion

Ocean Science ◽  
2011 ◽  
Vol 7 (4) ◽  
pp. 503-519 ◽  
Author(s):  
R. Sorgente ◽  
A. Olita ◽  
P. Oddo ◽  
L. Fazioli ◽  
A. Ribotti
Keyword(s):  
Numerical Simulation ◽  
Kinetic Energy ◽  
Energy Conversion ◽  
Ocean Model ◽  
Eddy Kinetic Energy ◽  
Tyrrhenian Sea ◽  
Central Mediterranean ◽  
Baroclinic Energy Conversion ◽  
Sicily Channel ◽  
Mean Kinetic Energy

Abstract. The spatial and temporal variability of eddy and mean kinetic energy of the Central Mediterranean region has been investigated, from January 2008 to December 2010, by mean of a numerical simulation mainly to quantify the mesoscale dynamics and their relationships with physical forcing. In order to understand the energy redistribution processes, the baroclinic energy conversion has been analysed, suggesting hypotheses about the drivers of the mesoscale activity in this area. The ocean model used is based on the Princeton Ocean Model implemented at 1/32° horizontal resolution. Surface momentum and buoyancy fluxes are interactively computed by mean of standard bulk formulae using predicted model Sea Surface Temperature and atmospheric variables provided by the European Centre for Medium Range Weather Forecast operational analyses. At its lateral boundaries the model is one-way nested within the Mediterranean Forecasting System operational products. The model domain has been subdivided in four sub-regions: Sardinia channel and southern Tyrrhenian Sea, Sicily channel, eastern Tunisian shelf and Libyan Sea. Temporal evolution of eddy and mean kinetic energy has been analysed, on each of the four sub-regions, showing different behaviours. On annual scales and within the first 5 m depth, the eddy kinetic energy represents approximately the 60 % of the total kinetic energy over the whole domain, confirming the strong mesoscale nature of the surface current flows in this area. The analyses show that the model well reproduces the path and the temporal behaviour of the main known sub-basin circulation features. New mesoscale structures have been also identified, from numerical results and direct observations, for the first time as the Pantelleria Vortex and the Medina Gyre. The classical kinetic energy decomposition (eddy and mean) allowed to depict and to quantify the permanent and fluctuating parts of the circulation in the region, and to differentiate the four sub-regions as function of relative and absolute strength of the mesoscale activity. Furthermore the Baroclinic Energy Conversion term shows that in the Sardinia Channel the mesoscale activity, due to baroclinic instabilities, is significantly larger than in the other sub-regions, while a negative sign of the energy conversion, meaning a transfer of energy from the Eddy Kinetic Energy to the Eddy Available Potential Energy, has been recorded only for the surface layers of the Sicily Channel during summer.

Lower plate extension of a retreating subduction zone: case study of the Sicily Channel Rift Zone

2021 ◽  
Author(s):  
Eline Le Breton ◽  
Mirko Carlini ◽  
Robert Neumeister ◽  
Jessica Ecke ◽  
Nicolo Chizzini ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Rift Zone ◽  
Western Mediterranean ◽  
Lower Plate ◽  
Accretionary Wedge ◽  
Tectonic Structures ◽  
Central Mediterranean ◽  
Adriatic Plate ◽  
Sicily Channel ◽  
Seismic Lines

<p>The Alpine-Mediterranean belt is remarkable because of the strong arcuation of its subduction front and the abundance of extensional basins developed within an overall compressional setting. Both resulted from rapid slab rollback and trench retreat especially in Neogene time, accompanied by upper-plate extension and the opening of the Western Mediterranean basins. The Strait of Sicily is a very interesting geological area in the Western-Central Mediterranean, as it has undergone tectonic extension and opening of a rift zone (Sicily Channel Rift Zone, SCRZ) on the lower plate (Africa) of the subduction zone, marked by the Gela Front and the Calabrian Accretionary Wedge, located south and south-east of Sicily, respectively. Furthermore, the SCRZ is important for understanding and quantifying the independent motion and counter-clockwise rotation of the Adriatic plate in Neogene time (Le Breton et al. 2017). However, the exact timing, tectonic style and amount of deformation along the SCRZ remain unclear.</p><p>To tackle these questions, we re-evaluate multichannel seismic reflection profiles across the SCRZ (CROP seismic lines M24 and M25), as well as a series of seismic lines correlated with boreholes data from the VIDEPI project (www.videpi.com). Main stratigraphic horizons and tectonic structures are mapped in a 3D database using the MOVE Software (provided by Petex). Preliminary results indicate ~30 km of NE-SW extension through the Pantelleria Rift and onset of syn-rift deposition during the upper Messinian, which could be related with the fast slab retreat of the Calabrian Arc.</p><p> </p><p><strong>References:</strong></p><p>Le Breton E., M.R. Handy, G. Molli and K. Ustaszewski (2017)<strong>. </strong>Post-20 Ma motion of the Adriatic plate – new constrains from surrounding orogens and implications for crust-mantle decoupling, Tectonics, doi:10.1002/2016TC004443</p>

scholarly journals The Impact of the Little Ice Age on Coccolithophores in the Central Mediterranea Sea

2010 ◽  
Vol 6 (6) ◽  
pp. 795-805 ◽  
Author(s):  
A. Incarbona ◽  
P. Ziveri ◽  
E. Di Stefano ◽  
F. Lirer ◽  
G. Mortyn ◽  
...  
Keyword(s):  
Little Ice Age ◽  
Vertical Mixing ◽  
Ice Age ◽  
Tyrrhenian Sea ◽  
Central Mediterranean ◽  
210Pb Activity ◽  
Decadal Scale ◽  
Lowermost Part ◽  
Sicily Channel ◽  
The Impact

Abstract. The Little Ice Age (LIA) is the last episode of a series of Holocene climatic anomalies. There is still little knowledge on the response of the marine environment to the pronounced cooling of the LIA and to the transition towards the 20th century global warming. Here we present decadal-scale coccolithophore data from four short cores recovered from the central Mediterranean Sea (northern Sicily Channel and Tyrrhenian Sea), which on the basis of 210Pb activity span the last 200–350 years. The lowermost part of the record of one of the cores from the Sicily Channel, Station 407, which extends down to 1650 AD, is characterized by drastic changes in productivity. Specifically, below 1850 AD, the decrease in abundance of F. profunda and the increase of placoliths, suggest increased productivity. The chronology of this change is related to the main phase of the Little Ice Age, which might have impacted the hydrography of the southern coast of Sicily and promoted vertical mixing in the water column. The comparison with climatic forcings points out the importance of stronger and prolonged northerly winds, together with decreased solar irradiance.

scholarly journals Calcareous nannofossil assemblages from the Central Mediterranean Sea over the last four centuries: the impact of the little ice age

2010 ◽  
Vol 6 (3) ◽  
pp. 817-866 ◽  
Author(s):  
A. Incarbona ◽  
P. Ziveri ◽  
E. Di Stefano ◽  
F. Lirer ◽  
G. Mortyn ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Little Ice Age ◽  
Ice Age ◽  
Tyrrhenian Sea ◽  
Calcareous Nannofossil ◽  
Central Mediterranean ◽  
Decadal Scale ◽  
Central Mediterranean Sea ◽  
Sicily Channel ◽  
The Impact

Abstract. We present decadal-scale calcareous nannofossil data from four short cores (Station 272, 37° 17' N, 12° 48' E, 226 m depth; St 342, 36° 42' N, 13° 55' E, 858.2 m depth; St 407, 36° 23' N, 14° 27' E, 345.4 m depth; C90-1M, 40° 36' N, 14° 42' E, 103.4 m depth) recovered in the central Mediterranean Sea (northern Sicily Channel and Tyrrhenian Sea), which, on the basis of 210Pb activity span the last 200–350 years. Assemblages are dominated by placoliths, mostly Emiliania huxleyi, while, at least in the Sicily Channel sediments, Florisphaera profunda was an important part of the coccolithophore community. The paleoenvironmental reconstruction, based on ecological preference of species and groups, suggests that the Tyrrhenian core C90-1M maintained higher productivity levels over recent centuries, with respect to the Sicily Channel sites, possibly because of more pronounced winter phytoplankton blooms, in agreement with modern primary productivity variations over the last ten years. The lowermost part of the record of one of the cores from the Sicily Channel, Station 407, which extends down to 1650 AD, is characterized by drastic changes in productivity. Specifically, below 1850 AD, the decrease in abundance of F. profunda and the increase of placoliths, suggest increased productivity. The chronology of this change is related to the main phase of the Little Ice Age, which might have impacted the hydrography of the southern coast of Sicily and promoted vertical mixing in the water column. The comparison with climatic forcings points out the importance of stronger and prolonged northerlies, together with decreased solar irradiance. The identification of the LIA in the northern Sicily Channel cover the Bond cycle BO that was missing in a previous study of Holocene climatic anomalies in the Sicily Channel. Finally, we suggest that major abundance changes in reworked nannofossil specimens, recorded in the Tyrrhenian core C90-1M, might be linked to variations in terrigenous supply from land. Paradoxically, higher amounts of reworking correspond to dry periods. We argue that soil and rock vulnerability is enhanced during times of prolonged drought and vegetation cover loss.

Imaging the Sicily Channel Rift Zone (Central Mediterranean) with seismic ambient noise tomography.

2020 ◽  
Author(s):  
Matthew Agius ◽  
Fabio Cammarano ◽  
Fabrizio Magrini ◽  
Claudio Faccenna ◽  
Francesca Funiciello ◽  
...  
Keyword(s):  
Seismic Tomography ◽  
Ambient Noise ◽  
Rift Zone ◽  
The South ◽  
Central Mediterranean ◽  
African Plate ◽  
Seismic Ambient Noise ◽  
Phase Velocities ◽  
Holistic Understanding ◽  
Sicily Channel

<p><span>The tectonics of the Sicily Channel, located in the Central Mediterranean, are thought to be driven by the Calabrian back-arc system moving south-eastwards and the north moving African plate. The Channel is characterized by a seismically and volcanically active rift zone, which extends for more than 600 km in length offshore from the south of Sardinia to the south-east of Malta. Much of the observations we have today are either limited to the surface and the upper crust, or are broader and deeper from regional seismic tomography, missing important details about the lithospheric structure and dynamics. The project GEOMED (</span><span>) addresses this issue by processing all the seismic data available in the region in order to understand better the geodynamics of the Central Mediterranean.</span></p><p><span>We use seismic ambient noise recorded on more than 50 stations located on Algeria, Italy (Lampedusa, Linosa, Pantelleria, Sardinia (LISARD seismic network), Sicily), Libya, Malta, and Tunisia to generate high-resolution seismic tomography maps for the region at different depths. We measure Rayleigh-wave phase velocities with periods ranging from 5 to 100 seconds sampling through the entire lithosphere. We find that at short periods (<25 s), paths of station-pairs crossing across Africa and Italy have slower velocities than those crossing the Tyrrhenian and Ionian basins indicating that these paths are sampling thick continental crust. However, station pairs limited to the Sicily Channel Rift Zone (SCRZ) have faster phase velocities for periods > 20 s comparable to those beneath the basins suggesting that the SCRZ has a thinner crust. The seismic velocity maps are compared with the regional tectonics, seismicity, volcanic activity and other geophysical studies to present a more holistic understanding of the processes involved.</span></p><p><span>This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 843696.</span></p>

DESIGN OF A EUROPEAN SURVEY ON THE PHARMACOLOGICAL MANAGEMENT OF PAEDIATRIC HEART FAILURE

2015 ◽  
Vol 101 (1) ◽  
pp. e1.64-e1
Author(s):  
Cristina Castro Díez ◽  
Feras Khalil ◽  
Michiel Dalinghaus ◽  
Marijke van der Meulen ◽  
Saskia de Wildt ◽  
...  
Keyword(s):  
Heart Failure ◽  
Drug Therapy ◽  
Survey Design ◽  
Therapeutic Strategies ◽  
Special Focus ◽  
The European Union ◽  
Converting Enzyme Inhibitors ◽  
Pharmacological Management ◽  
Survey Tool ◽  
Paediatric Cardiology

BackgroundLittle evidence is presently available to help clinicians guide decisions when tackling the pharmacological management of paediatric heart failure (HF). As a consequence, therapeutic strategies are largely supported by adults' data extrapolation and own expertise. The variability in drug treatment routines across Europe is expected to be high. Nevertheless, there are no epidemiological data that describe the current situation.AimTo develop a survey in the context of the LENA project to characterise the different therapeutic strategies for the management of paediatric HF that are currently practiced across Europe with special focus in the use of Angiotensin Converting Enzyme Inhibitors (ACE-I).MethodsItems to be included in the survey were selected through a thorough literature review and expert group discussions. European hospitals providing paediatric cardiology care were identified using websites of European and national paediatric cardiology associations as well as the ones of congresses and conferences related to the field. Standard recommendations for survey design were followed. The study protocol was approved by a data protection officer and an ethics committee. Web-survey tool EvaSys® was used. The survey was pre- and pilot-tested by a group of experts. A statistical analysis plan for the later processing and analysis of the data to be obtained was elaborated.ResultsA Europe-wide web-based survey was started in January 2015. 203 clinicians were invited via e-mail to participate. The questionnaire consisted of 23 questions addressing different aspects of drug therapy for HF in children. Use patterns of ACE-I (dosage by age group, effectiveness and toxicity assessment, use according to HF aetiology) and drug therapy for dilated cardiomyopathy where explored. Participants' demographic characteristics were also asked.ConclusionsThe procedure followed for the survey development should assure the quality of the tool. The results of this survey will provide an overview of the clinical treatment routine of paediatric heart failure across Europe.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n°602295 (LENA).The following authors will also be included in the later poster: Ingrid Klingmann (PHARMAPLEX BVBA, Germany), András Szatmári (GOTTSEGEN GYORGY ORSZAGOS KARDIOLOGIAI INTEZET, Hungary), László Ablonczy (GOTTSEGEN GYORGY ORSZAGOS KARDIOLOGIAI INTEZET, Hungary), Holger Schwender (HEINRICH-HEINE-UNIVERSITÄT DÜSSELDORF, GERMANY)

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