ALBERT

Description: Carbon dioxide deep geological storage, especially in deep saline aquifers, is one of the preferred technological options to mitigate the effects of greenhouse gases emissions. Thus, in the last decade, studies characterising the behaviour of potential CO2 deep geological storage sites along with thorough safety assessments have been considered essential in order to minimise the risks associated with these sites. The study of natural analogues represents the best source of reliable information about the expected hydrogeochemical processes involved in the CO2 storage in such deep saline aquifers. In this work, a comprehensive study of the hydrogeochemical features and processes taking place at the natural analogue of the Alicún de las Torres thermal system (Betic Cordillera) has been conducted. Thus, the main water/CO2/rock interaction processes occurring at the thermal system have been identified, quantified and modelled, and a principle conclusion is that the hydrogeochemical evolution of the thermal system is controlled by a global dedolomitization process triggered by gypsum dissolution. This geochemical process generates a different geochemical environment to that which would result from the exclusive dissolution of carbonates from the deep aquifer, which is generally considered as the direct result of CO2 injection in a deep carbonate aquifer. Therefore, discounting of the dedolomitization process in any CO2 deep geological storage may lead to erroneous conclusions. This process will also influence the porosity evolution of the CO2 storage formation, which is a very relevant parameter when evaluating a reservoir for CO2 storage. The geothermometric calculation performed in this work leads to estimate that the thermal water reservoir is located between 650 and 800 m depth, which is very close to the minimum required to inject CO2 in a deep geological storage. It is clear that the proper characterisation of the features and hydrogeochemical processes taking place at a natural system analogous to a man-made deep geological storage will provide useful conceptual, semi-quantitative and even quantitative information about the processes and consequences that may occur at the artificial storage system.

Description: This dataset includes 11 regional EUNIS-classified habitat maps (100-1000 km) and associated confidence maps that were created as a project milestone (Nr. 12) of the EU H2020 project 'iAtlantic'. The 12 iAtlantic regions encompass 1. Subpolar Mid-Atlantic Ridge, off Iceland MFRI, 2. Rockall Trough to PAP, 3. Central mid-Atlantic Ridge, 4. NW Atlantic, Gully Canyon, 5. Sargasso Sea, 6. Eastern Tropical North Atlantic, Cape Verde, 7. Equatorial Atlantic, Romanche Fracture Zone, 8. Slope & margin off Angola & Congo Lobe, 9. Benguela Current, Walvis Ridge to South Africa, 10. Brazil margin & Santos and Campos Basin, 11. Vitória-Trindade Seamount Chain and 12. Malvinas Current. For each of the regions 2-12, a shapefile of polygons classified according to the 2022 EUNIS classification level 3 and a second shapefile of the same polygons attributed with their confidence level according to the MESH Accuracy & Confidence Working approach was created. EUNIS classifications combined biozone and substrate data. Biozones were assigned from bathymetry. Where MBES was not available, GEBCO bathymetry was used. Substrate data were extracted from pre-existing geological/substrate mapping efforts and converted to EUNIS classifications via cross walks or, where substrate data were limited, substrate layers were modelled using Random Forest. The EUNIS habitat map for Region 4 was based on the pre-existing surficial geology compilation of the Scotian Shelf bioregion compiled by the Geological Survey of Canada. The EUNIS habitat map for Region 9 was based on the pre-existing South African habitat map that uses a modified IUCN hierarchical classification system. No additional information to that used in the EUSeaMap was available for Region 1. Therefore, shapefiles were not created for Region 1.

Description: This dataset includes 11 regional EUNIS-classified habitat maps (100-1000 km) and associated confidence maps that were created as a project milestone (Nr. 12) of the EU H2020 project 'iAtlantic'. The 12 iAtlantic regions encompass 1. Subpolar Mid-Atlantic Ridge, off Iceland MFRI, 2. Rockall Trough to PAP, 3. Central mid-Atlantic Ridge, 4. NW Atlantic, Gully Canyon, 5. Sargasso Sea, 6. Eastern Tropical North Atlantic, Cape Verde, 7. Equatorial Atlantic, Romanche Fracture Zone, 8. Slope & margin off Angola & Congo Lobe, 9. Benguela Current, Walvis Ridge to South Africa, 10. Brazil margin & Santos and Campos Basin, 11. Vitória-Trindade Seamount Chain and 12. Malvinas Current. For each of the regions 2-12, a shapefile of polygons classified according to the 2022 EUNIS classification level 3 and a second shapefile of the same polygons attributed with their confidence level according to the MESH Accuracy & Confidence Working approach was created. EUNIS classifications combined biozone and substrate data. Biozones were assigned from bathymetry. Where MBES was not available, GEBCO bathymetry was used. Substrate data were extracted from pre-existing geological/substrate mapping efforts and converted to EUNIS classifications via cross walks or, where substrate data were limited, substrate layers were modelled using Random Forest. The EUNIS habitat map for Region 4 was based on the pre-existing surficial geology compilation of the Scotian Shelf bioregion compiled by the Geological Survey of Canada. The EUNIS habitat map for Region 9 was based on the pre-existing South African habitat map that uses a modified IUCN hierarchical classification system. No additional information to that used in the EUSeaMap was available for Region 1. Therefore, shapefiles were not created for Region 1.

Description: This dataset includes 11 regional EUNIS-classified habitat maps (100-1000 km) and associated confidence maps that were created as a project milestone (Nr. 12) of the EU H2020 project 'iAtlantic'. The 12 iAtlantic regions encompass 1. Subpolar Mid-Atlantic Ridge, off Iceland MFRI, 2. Rockall Trough to PAP, 3. Central mid-Atlantic Ridge, 4. NW Atlantic, Gully Canyon, 5. Sargasso Sea, 6. Eastern Tropical North Atlantic, Cape Verde, 7. Equatorial Atlantic, Romanche Fracture Zone, 8. Slope & margin off Angola & Congo Lobe, 9. Benguela Current, Walvis Ridge to South Africa, 10. Brazil margin & Santos and Campos Basin, 11. Vitória-Trindade Seamount Chain and 12. Malvinas Current. For each of the regions 2-12, a shapefile of polygons classified according to the 2022 EUNIS classification level 3 and a second shapefile of the same polygons attributed with their confidence level according to the MESH Accuracy & Confidence Working approach was created. EUNIS classifications combined biozone and substrate data. Biozones were assigned from bathymetry. Where MBES was not available, GEBCO bathymetry was used. Substrate data were extracted from pre-existing geological/substrate mapping efforts and converted to EUNIS classifications via cross walks or, where substrate data were limited, substrate layers were modelled using Random Forest. No additional information to that used in the EUSeaMap was available for region 1. Therefore, shapefiles were not created for region 1.

Description: Caminella Lendenfeld, 1894 is a poorly known Geodiidae genus with unclear phylogenetic relationships. In order to find new lines of evidence that could shed light on the evolutionary history of Caminella, we decided to revise type material and museum material, as well as examine new material from underwater caves and deep-sea ecosystems. In doing so, we formally show that Isops maculosus Vosmaer, 1894 and Caminella loricata Lendenfeld, 1894 are junior synonyms of Caminella intuta (Topsent, 1892). We discuss different spicule morphological phenotypes in C. intuta, which may be linked to silica availability. We also discovered two new species of deep-sea Caminella: 1) from Cape Verde (Caminella caboverdensis sp. nov.) and 2) from seamounts located south of the Azores archipelago and the North of Spain (Caminella pustula sp. nov.). We reveal that Caminella sterrasters have complex surface microstructures, unique amongst the Geodiidae, where actin tips are linked to each other. Molecular markers (COI, 28S (C1-D2) and 18S) sequenced for some specimens led to new phylogenetic analyses, which continue to suggest a close relationship of Caminella with the Erylinae and Calthropella; these affinities are discussed in light of morphological characters.

Description: The continental shelf adjacent to the Río de la Plata (RdlP) exhibits extremely complex hydrographic and ecological characteristics which are of great socioeconomic importance. Since the long-term environmental variations related to the atmospheric (wind fields), hydrologic (freshwater plume), and oceanographic (currents and fronts) regimes are little known, the aim of this study is to reconstruct the changes in the terrigenous input into the inner continental shelf during the late Holocene period (associated with the RdlP sediment discharge) and to unravel the climatic forcing mechanisms behind them. To achieve this, we retrieved a 10 m long sediment core from the RdlP mud depocenter at 57 m water depth (GeoB 13813-4). The radiocarbon age control indicated an extremely high sedimentation rate of 0.8 cm per year, encompassing the past 1200 years (AD 750-2000). We used element ratios (Ti / Ca, Fe / Ca, Ti / Al, Fe / K) as regional proxies for the fluvial input signal and the variations in relative abundance of salinity-indicative diatom groups (freshwater versus marine-brackish) to assess the variability in terrigenous freshwater and sediment discharges. Ti / Ca, Fe / Ca, Ti / Al, Fe / K and the freshwater diatom group showed the lowest values between AD 850 and 1300, while the highest values occurred between AD 1300 and 1850. The variations in the sedimentary record can be attributed to the Medieval Climatic Anomaly (MCA) and the Little Ice Age (LIA), both of which had a significant impact on rainfall and wind patterns over the region. During the MCA, a weakening of the South American summer monsoon system (SAMS) and the South Atlantic Convergence Zone (SACZ), could explain the lowest element ratios (indicative of a lower terrigenous input) and a marine-dominated diatom record, both indicative of a reduced RdlP freshwater plume. In contrast, during the LIA, a strengthening of SAMS and SACZ may have led to an expansion of the RdlP river plume to the far north, as indicated by higher element ratios and a marked freshwater diatom signal. Furthermore, a possible multidecadal oscillation probably associated with Atlantic Multidecadal Oscillation (AMO) since AD 1300 reflects the variability in both the SAMS and SACZ systems.