The Graham Bank (Sicily Channel, central Mediterranean Sea): Seafloor signatures of volcanic and tectonic controls

Geomorphology ◽  
2018 ◽  
Vol 318 ◽  
pp. 375-389 ◽  
Author(s):  
D. Spatola ◽  
A. Micallef ◽  
A. Sulli ◽  
L. Basilone ◽  
R. Ferreri ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Central Mediterranean ◽  
Central Mediterranean Sea ◽  
Sicily Channel

The role of structural inheritance on Africa-Eurasia plate boundary evolution and neotectonics in the central Mediterranean sea

2021 ◽  
Author(s):  
Alina Polonia ◽  
Andrea Artoni ◽  
Graziella Barberi ◽  
Andrea Billi ◽  
Luca Gasperini ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Plate Boundary ◽  
Geophysical Data ◽  
Fault System ◽  
Central Mediterranean ◽  
Plate Convergence ◽  
Structural Inheritance ◽  
Central Mediterranean Sea ◽  
Sicily Channel ◽  
Subduction System

<p>Africa-Eurasia plate convergence and the retreat of the subducting slab led to the consumption of the Tethys ocean lithosphere, which has now mostly disappeared below or accreted/exhumed within the Alps/Apennines. Slab tearing plays a major role in plate boundary evolution, asthenospheric upwelling, dynamic topography and magmatism. However, the role played by structural inheritance on the Africa plate is not well constrained. Based on seismological, geodetic and marine geophysical data, we analyse the pattern of crustal deformation in the Calabrian Arc and Sicily Channel, two key regions to unravel the complex Africa/Eurasia plate interaction in the central Mediterranean Sea.</p><p>The Calabrian Arc subduction-rollback system accommodates Africa/Eurasia plate convergence along thrust faults developing both in the frontal and inner domains of the accretionary wedge. However, the most intriguing and tectonically active features are represented by arc-orthogonal faults deforming the subduction system along a complex strike-slip/transtensional pattern that may have been the source of major earthquakes in the Calabrian Arc. Deformation along the lithospheric transtensional faults is punctuated by buried sub-circular magnetized bodies aligned with Mt. Etna, that were interpreted as serpentinite/mud diapirs intruding the subduction system from the lower plate mantle. These faults are part of the overall dextral shear deformation, resulting from differences in Africa-Eurasia motion between the western and eastern sectors of the Tyrrhenian margin of northern Sicily, and accommodating diverging motions in the adjacent compartments of the Calabrian Arc. To the West, the Sicily Channel is part of the Pelagian block and experienced a lithospheric-scale continental rifting starting from the late Miocene with the development of NW-SE-trending tectonic depressions, bordered by crustal normal faults with variable throws. Our geophysical data, however, show that the most active tectonic feature in the area is a N-S trending and ~220-km-long lithospheric fault system characterized by volcanism, high heat flow and seismic activity. The NW-SE elongated rifting pattern, considered the first order structure in this region, appears currently inactive and sealed by undeformed Pleistocene deposits suggesting a recent change in structural development.</p><p>Seismological data show that the lithospheric boundaries present in the Calabrian Arc and Sicily Channel correlate well with spatial changes in the depth distribution of earthquakes and separate regions with different Moho depths and thickness of the seismogenic layer. We propose that these boundaries may represent long-lived inherited Mesozoic discontinuities controlling plate boundary evolution and neotectonics.</p>

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.

New insights on bottom water flows crossing a marine sill under periodic or impulsive perturbations: an application to the Sicily Channel sill (Central Mediterranean Sea)

2020 ◽  
Author(s):  
Federico Falcini ◽  
Marco Di Paolantonio ◽  
Ettore Salusti
Keyword(s):  
Mediterranean Sea ◽  
Red Sea ◽  
Deep Sea ◽  
Large Scale ◽  
Water Dynamics ◽  
Intermediate Water ◽  
Central Mediterranean ◽  
Geophysical Research ◽  
Central Mediterranean Sea ◽  
Sicily Channel

<p>We here discuss the remarkable uplift of the Eastern Mediterranean bottom waters that flow westward, over the Malta Escarpment, and cross the sill of the Channel of Sicily (Astarldi et al., 2001; Iudicone et al., 2003; Falcini & Salusti 2015); a dynamics that is rather similar to the one occurring at the Strait of Gibraltar (Mediterranean Sea) and Bab el Mandab (Red Sea) (Siddall et al., 2002). This classical uplift, which usually occurs under a three layer system dynamics, is mostly explained by the Bernoulli suction effect (Lane-Serff et al., 2000). However, the real filed analyses suggest that this dynamics are significantly perturbed by tidal effects and or large scale storms (Smeed et al., 2004). Here consider a novel, theoretical approach to obtain a rather realistic view of natural perturbations that affect these deep flow dynamics. Our insights on uplift processes, in addition, give a contribution to the general understanding of the Mediterranean Sea deep water circulation and, on climatological grounds, heat storage dynamics. We finally remark that similar phenomena happens in several marine straits and/or in semi-enclosed, peripheral basins of particular importance for local and large-scale processes.</p><p> </p><p><strong>References</strong></p><p>Astraldi, M., Gasparini, G. P., Gervasio, L., & Salusti, E. (2001). Dense water dynamics along the Strait of Sicily (Mediterranean Sea). Journal of Physical Oceanography, 31(12), 3457-3475.</p><p>Falcini, F., & Salusti, E. (2015). Friction and mixing effects on potential vorticity for bottom current crossing a marine strait: an application to the Sicily Channel (central Mediterranean Sea). Ocean Science, 11(3), 391-403.</p><p>Iudicone, D., Buongiorno Nardelli, B., Santoleri, R., & Marullo, S. (2003). Distribution and mixing of intermediate water masses in the Channel of Sicily (Mediterranean Sea). Journal of Geophysical Research: Oceans, 108(C9).</p><p>Lane-Serff, G. F., Smeed, D. A., & Postlethwaite, C. R. (2000). Multi-layer hydraulic exchange flows. Journal of Fluid Mechanics, 416, 269-296.</p><p>Siddall, M., Smeed, D. A., Matthiesen, S., & Rohling, E. J. (2002). Modelling the seasonal cycle of the exchange flow in Bab el Mandab (Red Sea). Deep Sea Research Part I: Oceanographic Research Papers, 49(9), 1551-1569.</p><p>Smeed, D. A. (2004). Exchange through the Bab el Mandab. Deep Sea Research Part II: Topical Studies in Oceanography, 51(4-5), 455-474.</p>

Predictive distribution models of European hake in the south-central Mediterranean Sea

Hydrobiologia ◽  
2017 ◽  
Vol 821 (1) ◽  
pp. 153-172 ◽  
Author(s):  
G. Garofalo ◽  
S. Fezzani ◽  
F. Gargano ◽  
G. Milisenda ◽  
O. Ben Abdallah ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Predictive Distribution ◽  
The South ◽  
Distribution Models ◽  
Central Mediterranean ◽  
South Central ◽  
Central Mediterranean Sea ◽  
European Hake

scholarly journals Air–Sea Interaction in the Central Mediterranean Sea: Assessment of Reanalysis and Satellite Observations

2021 ◽  
Vol 13 (11) ◽  
pp. 2188
Author(s):  
Salvatore Marullo ◽  
Jaime Pitarch ◽  
Marco Bellacicco ◽  
Alcide Giorgio di Sarra ◽  
Daniela Meloni ◽  
...  
Keyword(s):  
Heat Flux ◽  
Mediterranean Sea ◽  
Seasonal Cycle ◽  
Heat Fluxes ◽  
Meteorological Variables ◽  
Central Mediterranean ◽  
High Quality ◽  
Central Mediterranean Sea ◽  
In Situ Observations

Air–sea heat fluxes are essential climate variables, required for understanding air–sea interactions, local, regional and global climate, the hydrological cycle and atmospheric and oceanic circulation. In situ measurements of fluxes over the ocean are sparse and model reanalysis and satellite data can provide estimates at different scales. The accuracy of such estimates is therefore essential to obtain a reliable description of the occurring phenomena and changes. In this work, air–sea radiative fluxes derived from the SEVIRI sensor onboard the MSG satellite and from ERA5 reanalysis have been compared to direct high quality measurements performed over a complete annual cycle at the ENEA oceanographic observatory, near the island of Lampedusa in the Central Mediterranean Sea. Our analysis reveals that satellite derived products overestimate in situ direct observations of the downwelling short-wave (bias of 6.1 W/m2) and longwave (bias of 6.6 W/m2) irradiances. ERA5 reanalysis data show a negligible positive bias (+1.0 W/m2) for the shortwave irradiance and a large negative bias (−17 W/m2) for the longwave irradiance with respect to in situ observations. ERA5 meteorological variables, which are needed to calculate the air–sea heat flux using bulk formulae, have been compared with in situ measurements made at the oceanographic observatory. The two meteorological datasets show a very good agreement, with some underestimate of the wind speed by ERA5 for high wind conditions. We investigated the impact of different determinations of heat fluxes on the near surface sea temperature (1 m depth), as determined by calculations with a one-dimensional numerical model, the General Ocean Turbulence Model (GOTM). The sensitivity of the model to the different forcing was measured in terms of differences with respect to in situ temperature measurements made during the period under investigation. All simulations reproduced the true seasonal cycle and all high frequency variabilities. The best results on the overall seasonal cycle were obtained when using meteorological variables in the bulk formulae formulations used by the model itself. The derived overall annual net heat flux values were between +1.6 and 40.4 W/m2, depending on the used dataset. The large variability obtained with different datasets suggests that current determinations of the heat flux components and, in particular, of the longwave irradiance, need to be improved. The ENEA oceanographic observatory provides a complete, long-term, high resolution time series of high quality in situ observations. In the future, more similar sites worldwide will be needed for model and satellite validations and to improve the determination of the air–sea exchange and the understanding of related processes.

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