Levant Basin as a key for Understanding the Messinian Salinity Crisis: Challenging the Desiccation Paradigm

2020 ◽  
Author(s):  
Zohar Gvirtzman ◽  
Vinicio Manzi ◽  
Ran Calvo ◽  
Ittai Gavrieli ◽  
Rocco Gennari ◽  
...  
Keyword(s):  
High Resolution ◽  
Mediterranean Sea ◽  
Water Column ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Messinian Salinity Crisis ◽  
Seismic Surveys ◽  
Salt Rocks ◽  
The Mediterranean ◽  
Levant Basin

<p>The Messinian salinity crisis (MSC) is an extreme event in Earth history during which a salt giant (>1×10<sup>6</sup> km<sup>3</sup>) accumulated on the Mediterranean seafloor within ~640 kyrs. The Messinian salt giant was formed about 6 million years ago when the restriction of water exchanges between the Atlantic Ocean and the Mediterranean Sea turned the Mediterranean into an enormous saline basin. After more than 40 years of research, the timing and the depositional environments of shallow (<200 m) and intermediate (200-1000 m) water-depth Messinian basins are known quite well from onshore outcrops. But what happened in the deepest portions of the Mediterranean Sea is still unclear, because the information about offshore successions is mainly based on geophysical data with no rock samples that can be dated.</p> <p>The Levant Basin is the only deep Mediterranean basin where the entire Messinian section has been penetrated by wells tied to high resolution 3D seismic surveys. Here we present two studies challenging the desiccation paradigm dominating the MSC scientific literature for more than 40 years.</p> <p>The first study focuses on the nearly flat top erosion surface (TES) that truncates a basinward-tilted Messinian evaporitic succession. This truncation is commonly interpreted to be the result of subaerial erosion at the end of the MSC. However, based on high resolution seismic surveys and wireline logs, we show that (1) the TES is actually an intra-Messinian truncation surface (IMTS) located ~100 m below the Messinian-Zanclean boundary; (2) the topmost, post-truncation, Messinian unit is very different from the underlying salt deposits and consists mostly of shale, sand, and anhydrite showing typical <sup>87</sup>Sr/<sup>86</sup>Sr values and fauna assemblages from stage 3; and (3) the flat IMTS is a dissolution surface related to significant dilution and stratification of the water column during the transition from stage 2 to stage 3. We suggest that dissolution occurred upslope where salt rocks at the seabed were exposed to the upper diluted brine, while downslope the salt rocks were preserved because submerged in the deeper halite-saturated layer. The model, which requires a stratified water column, is inconsistent with a complete desiccation of the eastern Mediterranean Sea.</p> <p>The second study focuses on the onset of the Messinian salinity crisis in the deep Eastern Mediterranean basin. Biostratigraphy and astronomical tuning of the Messinian pre-salt succession in the Levant Basin allows for the first time the reconstruction of a detailed chronology of the MSC events in deep setting and their correlation with marginal records that supports the CIESM (2008) 3-stage model. Our main conclusions are (1) MSC events were synchronous across marginal and deep basins, (2) MSC onset in deep basins occurred at 5.97 Ma, (3) only foraminifera-barren, evaporite-free shales accumulated in deep settings between 5.97 and 5.60 Ma, (4) deep evaporites (sulfate and halite) deposition started later, at 5.60 Ma. The wide synchrony of events implies inter-sub-basin connection during the whole salinity crisis and is not compatible with large sea-level fall that would have separated the eastern and western basins producing diachronic processes.</p>

scholarly journals Satellite Observations of the Seasonal Evolution of Total Precipitable Water Vapour over the Mediterranean Sea

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
J. L. Palau ◽  
F. Rovira ◽  
M. J. Sales
Keyword(s):  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Precipitable Water ◽  
Satellite Observations ◽  
Annual Variability ◽  
Total Precipitable Water ◽  
New Findings ◽  
Precipitation Regimes ◽  
The Mediterranean

This study shows satellite observations and new findings on the time and spatial distribution of the Total Precipitable Water (TPW) column over the Mediterranean Sea throughout the year. Annual evolution and seasonality of the TPW column are shown and compared to the estimated net evaporation over the Mediterranean Sea. Daily spatiotemporal means are in good agreement with previous short-term field campaigns and also corroborate hypothesis and conclusions reached from previous mesoscale modelling studies: (a) from a meteorological point of view, Mediterranean Basin should be considered as two different subbasins (the Western and the Eastern Mediterranean); (b) accumulation processes may affect the radiative balance at regional scale and the summer precipitation regimes. Furthermore, these satellite observations constitute strong empirical evidences that, (a) from late May to early October, contrary to what happens in the Eastern Mediterranean Basin (EMB), there is a net accumulation of TPW on the Western Mediterranean Basin (WMB) that favours the instability of the atmosphere, (b) there is a seasonal anticorrelation between the seasonal variability of the TPW column over the two Mediterranean subbasins, (c) solar radiation can not be the only driver for the annual variability of the TPW column over the Mediterranean Sea, and (d) both previous features are seasonally dependent and, therefore, their effects on the TPW column are attenuated by annual variability.

scholarly journals High resolution nested model for the Cyprus, NE Levantine Basin, eastern Mediterranean Sea: implementation and climatological runs

2003 ◽  
Vol 21 (1) ◽  
pp. 221-236 ◽  
Author(s):  
G. Zodiatis ◽  
R. Lardner ◽  
A. Lascaratos ◽  
G. Georgiou ◽  
G. Korres ◽  
...  
Keyword(s):  
High Resolution ◽  
Mediterranean Sea ◽  
General Circulation ◽  
Eastern Mediterranean ◽  
Pilot Project ◽  
Ocean Model ◽  
Eastern Mediterranean Sea ◽  
Coastal Shelf ◽  
Forecasting System ◽  
The Mediterranean

Abstract. A high resolution nested flow model for the coastal, shelf and open sea areas of the Cyprus Basin, NE Levantine, eastern Mediterranean Sea is implemented to fulfil the objectives of the Mediterranean Forecasting System Pilot Project, funded by the EU. The Cyprus coastal ocean model is nested entirely within a coarse regional grid model of the eastern Mediterranean Sea, using the MODB climatology for initialisation and the ECMWF perpetual year surface forcing. The nested simulations of the Cyprus model were able to reproduce, with greater detail, flow features similar to those of the coarse grid regional model. The project results show the feasibility of the approach for the development of an operational forecasting system in the Mediterranean Sea, particularly in the Cyprus coastal/shelf sea area. Key words. Oceanography: general (descriptive and regional oceanography; numerical modelling) Oceanography: physical (general circulation)

scholarly journals Intercomparison of intense cyclogenesis events over the Mediterranean basin based on baroclinic and diabatic influences

2006 ◽  
Vol 7 ◽  
pp. 333-342 ◽  
Author(s):  
Ll. Fita ◽  
R. Romero ◽  
C. Ramis
Keyword(s):  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Numerical Study ◽  
Eastern Mediterranean ◽  
Geographical Area ◽  
Relative Weight ◽  
High Impact ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. A large number of high impact cyclones all over the Mediterranean basin have been reported on the data base of the MEDEX project (http://medex.inm.uib.es). A numerical study on the impacts and interactions of baroclinic and diabatic factors is carried out through a PV-based system of prognostic equations for 11 intense MEDEX cyclone episodes occurred in different zones of the basin (Western, Central and Eastern Mediterranean). The main aim of the study is to investigate the possible similarities and differences among the selected cases of the relative weight of the considered cyclogenetic factors on the cyclone evolutions as function of cyclone type and geographical area. A crucial role of the baroclinicity over the Mediterranean zone is obtained in most of the cases. A certain distinction can be also established in terms of the cyclogenesis areas (Africa, Mediterranean Sea, and Alpine region), and between west-central and eastern Mediterranean basins. It is generally observed that the considered baroclinic and diabatic factors cooperate most strongly for the cyclone deepening process when the disturbance reaches the Mediterranean sea.

scholarly journals New records of amphipod crustaceans along the Israeli Mediterranean coast, including a rare Mediterranean endemic species, Maera schieckei Karaman & Ruffo, 1971

2020 ◽  
Vol 8 ◽  
Author(s):  
Sabrina Lo Brutto ◽  
Davide Iaciofano
Keyword(s):  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Aegean Sea ◽  
Western Mediterranean ◽  
Mediterranean Coast ◽  
Tyrrhenian Sea ◽  
Western Mediterranean Basin ◽  
The Mediterranean ◽  
Distribution And Ecology

A survey has been carried out at four Israeli rocky sites to evaluate the diversity of the amphipod fauna on various hard substrates, still scarcely monitored, as potential pabulum for amphipod crustacean species. A survey of shallow rocky reefs along the Mediterranean coast of Israel recovered 28 species and integrated the Amphipoda checklist for the country ofIsrael with 12 newly-recorded species. Such renewed national list includes Maera schieckei Karaman & Ruffo, 1971, a rare species endemic to the Mediterranean Sea, recorded here for the first time from the southern Levant Basin. The species, described from specimens collected in the Tyrrhenian Sea in 1970, has been only recorded eight times within the whole Mediterranean Sea. A revision of the bibliography on the distribution and ecology of M. schieckei showed that, although mentioned only for the western Mediterranean basin by some authors, it is listed in the checklist of amphipods of the Aegean Sea and neighbouring seas and has been found in the eastern Mediterranean basin since 1978. Maera schieckei was rarely found in the Mediterranean, one of the most studied marine biogeographic region as concerns the amphipod fauna; and the species seems to prefer bays or gulf areas. The role of updating and monitoring faunal composition should be re-evaluated.

scholarly journals Calcareous dinoflagellate turnover in relation to the Messinian salinity crisis in the eastern Mediterranean Pissouri Basin, Cyprus

2007 ◽  
Vol 26 (2) ◽  
pp. 103-116 ◽  
Author(s):  
Katarzyna-Maria Bison ◽  
Gerard J. M. Versteegh ◽  
Frits J. Hilgen ◽  
Helmut Willems
Keyword(s):  
Mediterranean Basin ◽  
Phytoplankton Community ◽  
Environmental Changes ◽  
Eastern Mediterranean ◽  
Messinian Salinity Crisis ◽  
Low Diversity ◽  
Restricted Environment ◽  
The Mediterranean ◽  
Upper Tortonian ◽  
The Mediterranean Basin

Abstract. The extent to which the Messinian salinity crisis modified the initially Tethyan, eastern Mediterranean phytoplankton community has been investigated by monitoring the fate of calcareous dinoflagellate cyst assemblages prior to, during and after the salinity crisis in the Pissouri section (Cyprus). A rich, but low diversity open oceanic assemblage, dominated by Calciodinellum albatrosianum, is found in the upper Tortonian and lower Messinian. The upper Messinian (pre-evaporitic) sediments yield only few cysts but the assemblage is much more diverse and reflects unstable more neritic conditions (Bicarinellum tricarinelloides), fluvial influence (Leonella granifera) and varying, temporally increased salinities (Pernambugia tuberosa), probably related to the increasingly restricted environment. The basal Pliocene sediments reflect the return to normal marine conditions; the dinoflagellate assemblage is rich in cysts and again has a low diversity. However, in contrast to the C. albatrosianum-dominated upper Tortonian and pre-evaporitic Messinian sediments, L. granifera clearly dominates the basal Pliocene association just after the replenishment of the Mediterranean basin. Apart from this shift in dominance, the onset of the Pliocene is furthermore marked by the first appearance of Calciodinellum elongatum, which must have immigrated from the Atlantic Ocean. Lebessphaera urania, a postulated remnant of the Tethyan Ocean survived the salinity crisis, possibly in as yet unidentified marine refuges in the Mediterranean itself. Although the environmental changes caused by the Messinian salinity crisis did not lead to an extinction of calcareous dinoflagellate species of the Pissouri Basin, it resulted in a significant change in the assemblages and contributed to a more modern character of the Pliocene dinoflagellate association in the eastern Mediterranean.

scholarly journals Integrated survey of elemental stoichiometry (C, N, P) from the western to eastern Mediterranean Sea

2011 ◽  
Vol 8 (4) ◽  
pp. 883-899 ◽  
Author(s):  
M. Pujo-Pay ◽  
P. Conan ◽  
L. Oriol ◽  
V. Cornet-Barthaux ◽  
C. Falco ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Water Column ◽  
Eastern Mediterranean ◽  
Western Basin ◽  
Nutrient Sources ◽  
P Limitation ◽  
Elemental Stoichiometry ◽  
Deep Layers ◽  
Redfield Ratios ◽  
The Mediterranean

Abstract. This paper provides an extensive vertical and longitudinal description of the biogeochemistry along an East-West transect of 3000 km across the Mediterranean Sea during summer 2008 (BOUM cruise). During this period of strong stratification, the distribution of nutrients, particulate and dissolved organic carbon (DOC), nitrogen (DON) and phosphorus (DOP) were examined to produce a detailed spatial and vertically extended description of the elemental stoichiometry of the Mediterranean Sea. Surface waters were depleted in nutrients and the thickness of this depleted layer increased towards the East from about 10 m in the Gulf of Lion to more than 100 m in the Levantine basin, with the phosphacline deepening to a greater extent than that for corresponding nitracline and thermocline depths. We used the minimum oxygen concentration through the water column in combination with 2 fixed concentrations of dissolved oxygen to distinguish an intermediate layer (Mineralization Layer; ML) from surface (Biogenic Layer; BL), and deep layers (DL). Whilst each layer was represented by different water masses, this approach allowed us to propose a schematic box-plot representation of the biogeochemical functioning of the two Mediterranean basins. Despite the increasing oligotrophic nature and the degree of P-depletion along the West to East gradient strong similarities were encountered between eastern and western ecosystems. Within the BL, the C:N:P ratios in all pools largely exceeded the Redfield ratios, but surprisingly, the nitrate vs. phosphate ratios in the ML and DL tended towards the canonical Redfield values in both basins. A change in particulate matter composition has been identified by a C increase relative to N and P along the whole water column in the western basin and between BL and ML in the eastern one. Our data showed a noticeable stability of the DOC:DON ratio (12–13) throughout the Mediterranean Sea. This is in good agreement with a P-limitation of microbial activities but in contradiction of the accepted concept that N is recycled faster than C. The western and eastern basins had similar or close biological functioning. Differences come from variability in the allochtonous nutrient sources in terms of quantity and quality, and to the specific hydrodynamic features of the Mediterranean basins.

Monitoring and forecasting of marine pollution in the Mediterranean Sea: the ODYSSEA project approach

2020 ◽  
Author(s):  
Katerina Spanoudaki ◽  
Nikolaos Kokkos ◽  
Konstantinos Zachopoulos ◽  
Georgios Sylaios ◽  
Nikolaos Kampanis ◽  
...  
Keyword(s):  
Water Quality ◽  
High Resolution ◽  
Mediterranean Sea ◽  
Oil Spill ◽  
Mediterranean Basin ◽  
Shelf Zone ◽  
Forecasting System ◽  
Marine Data ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>The H2020 funded project ODYSSEA (http://odysseaplatform.eu/) aims to make Mediterranean marine data easily accessible and operational to a broad range of users of the marine space. ODYSSEA develops an interoperable and cost-effective platform, fully integrating networks of observing and forecasting systems across the Mediterranean basin, addressing both the open sea and the coastal zone. The platform integrates marine data from existing Earth Observing Systems, such as Copernicus and EMODnet, receives and processes novel, newly produced datasets (through high-resolution models and on-line sensors such as a novel microplastics sensor) from nine prototype Observatories established across the Mediterranean basin, and applies advanced algorithms to organise, homogenise and fuse the large quantities of data in order to provide to various end-user groups and stakeholders both primary data and on-demand derived data services.</p><p>The nine ODYSSEA Observatories are established across the whole Mediterranean basin, covering also areas of marine data gaps along the North African and Middle East coastline. The Observatories comprise observing and forecasting systems and cover coastal and shelf zone environments, Marine Protected Areas and areas with increased human pressure. The operational forecasting system of the Observatories consists of a ‘chain’ of dynamically coupled, high-resolution numerical models comprised of a) the hydrodynamic model Delft3D-FLOW, b) the wave model Delft3D-WAVE (SWAN), c) the water quality model DELWAQ, d) the oil spill fate and transport model MEDSLIK-II, e) the ecosystem model ECOPATH, and f) the in-house mussel farm model developed by the Democritus University of Thrace. This operational system provides forecasts, early warnings and alerts for currents, waves, water quality parameters, oil spill pollution and ecosystem status. In this work, the ODYSSEA forecasting system (developed with the Delft-FEWS software) is implemented for simulating oil spill pollution for the Thracian Sea Observatory.  The area is biodiversity rich and an important spawning and nursery ground for small pelagic species, while in Kavala Gulf, oil exploitation takes place. The Lagrangian oil spill model MEDSLIK-II has been coupled to high-resolution oceanographic fields (currents, temperature, Stokes drift velocity), produced by Delft3D-FLOW and SWAN, and NOAA GFS atmospheric forcing. The hydrodynamic and wave models have been configured for the Thracian Sea based on dynamic downscaling of CMEMS products to a grid resolution of 1/120°. Seasonal hazard maps (surface oil slick, beached oil) are produced employing multiple oil spill scenarios using multi-year hydrodynamics. The results highlight the hazard faced by Thracian Sea Observatory coasts. </p><p><strong>Acknowledgements:</strong> This research has received funding from the European Union’s Horizon 2020 research and innovation programme ODYSSEA: OPERATING A NETWORK OF INTEGRATED OBSERVATORY SYSTEMS IN THE MEDITERRANEAN SEA, GA No 72727.</p>

scholarly journals Hydrography in the Mediterranean Sea during a cruise with RV <i>Poseidon</i> in April 2014

2015 ◽  
Vol 7 (2) ◽  
pp. 231-237 ◽  
Author(s):  
D. Hainbucher ◽  
V. Cardin ◽  
G. Siena ◽  
U. Hübner ◽  
M. Moritz ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Water Column ◽  
Eastern Mediterranean ◽  
Acoustic Doppler Current Profiler ◽  
Intermediate Water ◽  
German Research ◽  
Current Profiler ◽  
The Mediterranean ◽  
Vertical Spacing

Abstract. We report on data from an oceanographic cruise in the Mediterranean Sea on the German research vessel Poseidon in April 2014. Data were taken on a west–east section, starting at the Strait of Gibraltar and ending south-east of Crete, as well on sections in the Ionian and Adriatic Sea. The objectives of the cruise were threefold: to contribute to the investigation of the spatial evolution of the Levantine Intermediate Water (LIW) properties and of the deep water masses in the eastern Mediterranean Sea, and to investigate the mesoscale variability of the upper water column. The measurements include salinity, temperature, oxygen and currents and were conducted with a conductivity, temperature and depth(CTD)/rosette system, an underway CTD and an acoustic Doppler current profiler (ADCP). The sections are on tracks which have been sampled during several other cruises, thus supporting the opportunity to investigate the long-term temporal development of the different variables. The use of an underway CTD made it possible to conduct measurements of temperature and salinity with a high horizontal spacing of 6 nm between stations and a vertical spacing of 1 dbar for the upper 800 m of the water column.

scholarly journals ​Impact of changes in rivers inputs during the last decades on the biogeochemistry of the eastern Mediterranean basin

2020 ◽  
Author(s):  
Rémi Pagès ◽  
Melika Baklouti ◽  
Nicloas Barrier ◽  
Camille Richon ◽  
Jean-Claude Dutay ◽  
...  
Keyword(s):  
Surface Layer ◽  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Large Scale ◽  
Eastern Mediterranean ◽  
Phosphate Availability ◽  
Eastern Mediterranean Basin ◽  
The Mediterranean ◽  
Long Term Impact ◽  
First Time

&lt;p&gt;The Mediterranean Sea (MS) is a semi-enclosed sea characterized by a zonal west-east gradient of oligotrophy, where microbial growth is controlled by phosphate availability in most situations. External inputs of nutrients including Gibraltar inputs, river inputs and atmospheric deposition are therefore of major importance for the biogeochemistry of the MS. The latter has long been considered to be driven mainly by nutrient exchanges at Gibraltar. However, recent studies indicate that river inputs significantly affect nutrients concentrations in the Mediterranean Sea, although their resulting impact on its biogeochemistry remains poorly understood. In this study, our aim was to help fill this knowledge gap by addressing the large-scale and long-term impact of variations in river inputs on the biogeochemistry of the Mediterranean Sea over the last decades, using a coupled physical- biogeochemical 3D model (NEMO-MED12/Eco3M-Med). As a first result, it has been shown by the model that the strong diminution (60%) of phosphate (PO4) in river inputs into the Mediterranean Sea since the end of the 1980s induced a significant lowering of PO4 availability in the sub-surface layer of the Eastern Mediterranean Basin (EMB). One of the main consequences of PO4 diminution is the rise, never previously documented, of dissolved organic carbon (DOC) concentrations in the surface layer (by 20% on average over the EMB). Another main result concerns the gradual deepening of the top of the phosphacline during the period studied, thus generating a shift between the top of the nitracline and the top of the phosphacline in the EMB. This shift has already been observed in situ and documented in literature, but we propose here a new explanation for its occurrence in the EMB. The last main result is the evidence of the decline in abundance and the reduction of size of copepods calculated by the model over the years 1985&amp;#8211;2010, that could partially explain the reduction in size of anchovy and sardine recently recorded in the MS. In this study, it is shown for the first time that the variations in river inputs that occurred in the last decades may have significantly altered the biogeochemical cycles of two key elements (P and C), in particular in the EMB.&lt;/p&gt;

Sign in / Sign up

Export Citation Format

Share Document