Description: Submarine landslides can destroy seafloor infrastructure and generate devastating tsunamis, but in spite of decades of research into the functioning of submarine landslides there are still numerous open questions in particular how different phases of sliding influence each other. Here, we re-analyse the Ana Slide - a relatively small (〈1 km3) landslide in the Balearic Islands, which is unique because it is completely imaged by high-resolution 3D seismic data. The Ana Slide comprises three domains: (i) a source area that is almost completely evacuated with evidence of headscarp retrogression; (ii) an adjacent downslope translational domain representing a bypass zone for the material that was mobilized in the source area, and (iii) the deposit formed by the mobilized material, which accumulated downslope in a sink area. Isochron maps show deep chaotic seismic units underneath the thickest deposits. We infer that rapid deposition of the landslide material deformed the underlying sediments. A thin stratified sedimentary unit between three lobes shows that the Ana Slide evolved in two failure stages separated by several tens of thousands of years. This illustrates the danger of over-estimating the volume of mobilized material and under-estimating the complexity even of relatively simple slope failures without high-quality seismic data.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Pedrosa-Pamies, R., Parinos, C., Sanchez-Vidal, A., Calafat, A., Canals, M., Velaoras, D., Mihalopoulos, N., Kanakidou, M., Lampadariou, N., & Gogou, A. Atmospheric and oceanographic forcing impact particle flux composition and carbon sequestration in the eastern Mediterranean Sea: a three-year time-series study in the deep Ierapetra Basin. Frontiers in Earth Science, 9, (2021): 591948, https://doi.org/10.3389/feart.2021.591948.

Description: Sinking particles are a critical conduit for the export of organic material from surface waters to the deep ocean. Despite their importance in oceanic carbon cycling, little is known about the biotic composition and seasonal variability of sinking particles reaching abyssal depths. Herein, sinking particle flux data, collected in the deep Ierapetra Basin for a three-year period (June 2010 to June 2013), have been examined at the light of atmospheric and oceanographic parameters and main mass components (lithogenic, opal, carbonates, nitrogen, and organic carbon), stable isotopes of particulate organic carbon (POC) and source-specific lipid biomarkers. Our aim is to improve the current understanding of the dynamics of particle fluxes and the linkages between atmospheric dynamics and ocean biogeochemistry shaping the export of organic matter in the deep Eastern Mediterranean Sea. Overall, particle fluxes showed seasonality and interannual variability over the studied period. POC fluxes peaked in spring April–May 2012 (12.2 mg m−2 d−1) related with extreme atmospheric forcing. Summer export was approximately fourfold higher than mean wintertime, fall and springtime (except for the episodic event of spring 2012), fueling efficient organic carbon sequestration. Lipid biomarkers indicate a high relative contribution of natural and anthropogenic, marine- and land-derived POC during both spring (April–May) and summer (June–July) reaching the deep-sea floor. Moreover, our results highlight that both seasonal and episodic pulses are crucial for POC export, while the coupling of extreme weather events and atmospheric deposition can trigger the influx of both marine labile carbon and anthropogenic compounds to the deep Levantine Sea. Finally, the comparison of time series data of sinking particulate flux with the corresponding biogeochemical parameters data previously reported for surface sediment samples from the deep-sea shed light on the benthic–pelagic coupling in the study area. Thus, this study underscores that accounting the seasonal and episodic pulses of organic carbon into the deep sea is critical in modeling the depth and intensity of natural and anthropogenic POC sequestration, and for a better understanding of the global carbon cycle.

Description: This research was supported by the REDECO (CTM2008-04973-E/MAR) and PERSEUS (GA 287600) projects. We further acknowledge support by the projects PANACEA—‘PANhellenic infrastructure for Atmospheric Composition and climatE chAnge’ (MIS 5021516) and ENIRISST—‘Intelligent Research Infrastructure for Shipping, Supply Chain, Transport and Logistics’ (MIS 5027930), which are implemented under the Action “Reinforcement of the Research and Innovation Infrastructure,” funded by the Operational Program “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020) and co-financed by Greece and EU; and by the Action “National Νetwork on Climate Change and its Impacts - Climpact” which is implemented under the sub-project 3 of the project “Infrastructure of national research networks in the fields of Precision Medicine, Quantum Technology and Climate Change,” funded by the Public Investment Program of Greece, General Secretary of Research and Technology/Ministry of Development and Investments.” Researchers from GRC Geociències Marines benefited from a Grups de Recerca Consolidats grant (2017 SGR 315) by Generalitat de Catalunya autonomous government.

Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tarrés, M., Cerdà-Domènech, M., Pedrosa-Pàmies, R., Rumín-Caparrós, A., Calafat, A., Canals, M., & Sanchez-Vidal, A. Particle fluxes in submarine canyons along a sediment-starved continental margin and in the adjacent open slope and basin in the SW Mediterranean Sea. Progress in Oceanography, 203, (2022): 102783, https://doi.org/10.1016/j.pocean.2022.102783.

Description: Investigating the transfer of particulate matter from the continental shelf to the deep basin is critical to understand the functioning of deep sea ecosystems. In this paper we present novel results on the temporal variability of particle fluxes to the deep in three physiographic domains of a 240 km long margin segment and nearby basin off Murcia and Almeria provinces in the SW Mediterranean Sea, which are submarine canyons forming a rather diverse set (namely Escombreras, Garrucha-Almanzora and Almeria), the adjacent open slope and the deep basin. This margin is located off one of the driest regions in Europe and, therefore, its study may help understanding how mainland aridity translates into the export of particles to deep margin environments. Five mooring lines equipped with currentmeters, turbidity-meters and sediment traps were deployed for one entire annual cycle, from March 2015 to March 2016. We combine oceanographic, hydrological and meteorological data with grain size and bulk elemental data (organic carbon, opal, CaCO3, lithogenic) from the collected sinking particles to understand what drives particle transfers in such an under-studied setting, and to quantify the resulting fluxes and assess their spatio-temporal variability. Weighted total mass fluxes in canyons range from 1.64 g m−2 d−1 in Almeria Canyon to 7.33 g m−2 d−1 in Garrucha-Almanzora Canyon system, which are rather low values compared to other submarine canyons in the Western Mediterranean Sea. This results from the absence of extreme wind-storm events during the investigated time period combined with the reduced sediment input to the inner shelf by river systems in the study area. Our results also show that wind-storms are the main trigger for off-shelf particle transport to the deep margin, both within submarine canyons and over the open slope. The most significant transfer period is associated to a set of north-eastern storms in early spring 2015, when the off-shelf transport likely was promoted by storm-induced downwelling. However, the prevailing oceanographic conditions restricts the advection of water down the canyon heads to a few hundred meters, thus promoting a bottom-detached transport of particles seaward. Overall physiography, canyon head incision into the continental shelf and the distance of the canyon head to the shoreline (e.g. very short in Garrucha Canyon) play a key role in particle trapping capability and, therefore, in easing downslope particle transport. Further, bottom trawling activities around the Garrucha-Almanzora Canyon system, feed a nepheloid layer at depths in excess of 400 m, subsequently enhancing particle fluxes throughout the study period. In contrast, maximum particle fluxes in the deep basin respond to seasonal phytoplankton blooms. Our study shows that particle export from the shallow inner margin to the deep outer margin in sediment-starved settings, even if limited, does occur as dominated by atmosphere and ocean driven short-lived events. However, that export does not reach too far as at several tens of kilometres from the shelf edge advective fluxes are replaced by vertical ones impelled by phytoplankton dynamics.

Description: This work was supported by research projects NUREIEV (ref. CTM2013-44598-R) and NUREIEVA (ref. CTM2016-75953-C2-1-R). GRC Geociències Marines is funded by the Catalan Government within its excellence research groups program (ref. 2017 SGR 315). M.Tarrés was supported by a FPI grant from Ministerio de Ciencia, Innovación y Universidades of the Spanish Government.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Fanelli, E., Bianchelli, S., Foglini, F., Canals, M., Castellan, G., Guell-Bujons, Q., Galil, B., Goren, M., Evans, J., Fabri, M.-C., Vaz, S., Ciuffardi, T., Schembri, P. J., Angeletti, L., Taviani, M., & Danovaro, R. Identifying priorities for the protection of deep Mediterranean Sea ecosystems through an integrated approach. Frontiers in Marine Science, 8, (2021): 698890, https://doi.org/10.3389/fmars.2021.698890.

Description: Benthic habitats of the deep Mediterranean Sea and the biodiversity they host are increasingly jeopardized by increasing human pressures, both direct and indirect, which encompass fisheries, chemical and acoustic pollution, littering, oil and gas exploration and production and marine infrastructures (i.e., cable and pipeline laying), and bioprospecting. To this, is added the pervasive and growing effects of human-induced perturbations of the climate system. International frameworks provide foundations for the protection of deep-sea ecosystems, but the lack of standardized criteria for the identification of areas deserving protection, insufficient legislative instruments and poor implementation hinder an efficient set up in practical terms. Here, we discuss the international legal frameworks and management measures in relation to the status of habitats and key species in the deep Mediterranean Basin. By comparing the results of a multi-criteria decision analysis (MCDA) and of expert evaluation (EE), we identify priority deep-sea areas for conservation and select five criteria for the designation of future protected areas in the deep Mediterranean Sea. Our results indicate that areas (1) with high ecological relevance (e.g., hosting endemic and locally endangered species and rare habitats),(2) ensuring shelf-slope connectivity (e.g., submarine canyons), and (3) subject to current and foreseeable intense anthropogenic impacts, should be prioritized for conservation. The results presented here provide an ecosystem-based conservation strategy for designating priority areas for protection in the deep Mediterranean Sea.

Description: This study was supported by the DG ENV project IDEM (Implementation of the MSFD to the Deep Mediterranean Sea; contract EU No. 11.0661/2017/750680/SUB/EN V.C2). MC and QG-B acknowledge support from Generalitat de Catalunya autonomous government through its funding scheme to excellence research groups (Grant 2017 SGR 315).