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Detailed knowledge of the shape of the seafloor is crucial to humankind. Bathymetry data is critical for safety of navigation and is used for many other applications. In an era of ongoing environmental degradation worldwide, bathymetry data (and the knowledge derived from it) play a pivotal role in using and managing the world’s oceans in a way that is in accordance with the United Nations Sustainable Development Goal 14 - conserve and sustainably use the oceans, seas and marine resources for sustainable development. However, the vast majority of our oceans is still virtually unmapped, unobserved, and unexplored. Only a small fraction of the seafloor has been systematically mapped by direct measurement. The remaining bathymetry is predicted from satellite altimeter data, providing only an approximate estimation of the shape of the seafloor. Several global and regional initiatives are underway to change this situation. This paper presents a selection of these initiatives as best practice examples for bathymetry data collection, compilation and open data sharing as well as the Nippon Foundation-GEBCO (The General Bathymetric Chart of the Oceans) Seabed 2030 Project that complements and leverages these initiatives and promotes international collaboration and partnership. Several non-traditional data collection opportunities are looked at that are currently gaining momentum as well as new and innovative technologies that can increase the efficiency of collecting bathymetric data. Finally, recommendations are given towards a possible way forward into the future of seafloor mapping and towards achieving the goal of a truly global ocean bathymetry.

Prior to the 4th annual AtlantOS meeting in month 48 a project progress report for the external project boards (EB and ISTAB) will be prepared to enable them to be as good as possible prepared for the meeting and to ensure consequently that AtlantOS receives as constructive as possible recommendations from the boards. This report, together with the two external summary board meeting reports, which will be requested from the EB and ISTAB, will represent D11.7.

Development and dissemination of up to 6 visual / interactive outputs aimed at stakeholder groups

Version No.:1.2. -Implementation of AtlantOS Catalogue and GEOSS requirements

Prior to the 3rd annual meeting in month 32 a project progress report for the external project boards will be prepared to enable them to as good as possible prepared for the meeting and to ensure consequently that AtlantOS receives as constructive as possible recommendations from the board. The report together with the external summary board meeting report will be part of D11.6

A number of prototypes equipped with different sensors (if more than one exists) will be tested at sea with different methods to avoid bio-fouling. CNRS will conduct evaluation of the test performed by NKE

AtlantOS Deliverable

AtlantOS Deliverable

Design, initial content loading and launch of AtlantOS project website www.atlantos-h2020.eu

As the world faces the consequences of rising anthropogenic carbon dioxide entering the atmosphere and ultimately the ocean, a growing arsenal of adaptation and mitigation strategies are being investigated. Carbon dioxide capture and storage (CCS) is regarded as a useful way of removing CO2 at source, transporting it and storing it at depth underground, in saline aquifers or depleted hydrocarbon reservoirs beneath the seabed. But will there be any impacts in the marine environment above these sites? Anja Reitz describes how one EC- funded project hopes to find the answers.

The aim of the cruise was to investigate the gas hydrate distribution in sediments of the Black Sea by using several coring technics. Drill sites with the portable drilling system MeBo should extend the normal coverage of the dynamic autoclave piston corer (DAPC) and gravity cores into deeper sediments down to 30-50 m below seafloor. In addition to the coring activities the newly installed EM122 and the PARASOUND system should be used for gas emissions to the water column. The MeBo system was deployed at four sites and drilled altogether 52 m sediments and massive gas hydrates at Pechori Mound. Unfortunately the drilling operation with MeBo had to be canceled after failure of the hydraulic system. In total 10 DAPC, 46 gravity cores and 21 mini corer samplings have been successfully performed. PARASOUND and the multibeam (EM122) were recorded for 17 days and 23 hours in Ukrainian, Turkish and Georgian waters in order to measure gas emissions from the seafloor by flare imaging. EM122 surveys have been extremely useful in both the western (Eregli) and eastern (Ordu Ridge) areas of the Turkish continental margin, where backscatter analyses guided us to the areas of shallow gas hydrates. In Georgia selected areas with SAR satellite-imaged oil slicks have been investigated for their gas flares and sediment composition. In two areas on the western and eastern Kulevi Ridge oil-rich sediments were sampled in association with the gas flares. In Ukraine Kerch flare and Helgoland mud volcano have been very successfully investigated for their temperature gradients and their gas hydrate presence in near-surface sediments., METEOR-Berichte

The simultaneous and independent determination of the radiogenic (87Sr/86Sr) and the fractionation reflecting stable (!88/86Sr) Sr isotope ratio on pore waters, sediments and precipitates (e.g. carbonates and sulfates) opens a new perspective in the field of submarine weathering and Sr contribution to the ocean chemistry. Four initial case studies covering (1.) CO2 seeps of the Okinawa Trough (OT), (2.) mud volcanoes (MV) and mounds in the Gulf of Cadiz (GoC) and the (3.) Central American Fore Arc as well as first results from the (4.) Black Sea are conducted and reflect a stable Sr perspective on seeps from a broad range of geological settings. Referred to NIST-SRM-987, in this study the IAPSO seawater (SW) standard has a !88/86Sr of 0.39 ‰ (±0.03, 2SD). As a prominent systematic deviation the OT pore water (PW) data from a site with CO2 hydrate and liquid CO2 occurence show values ranging from 0.27 to 0.59 ‰ (286 to 64 cm sediment depth), accompanied by a weak inversely correlated trend from 0.2 to 0.15 ‰ for the corresponding bulk sediment (286 to 36 cm). In contradiction to a simple fluid/SW-mixing approach as driving mechanism for the PW stable Sr trend the 87Sr/86Sr signature stays within analytical uncertainty constant with depth (0.70980 (1)) and differs significantly from SW (0.70917 (1)) and the more radiogenic, slightly heterogeneous sediment (0.71892-0.71731). Potential explanation for the observed !88/86Sr trend and PW signatures heavier than SW are (a) strong fractionation processes enriching light isotopes in secondary precipitates and remineralisation products and heavier signatures in the remaining fluid and/or (b) preferential dissolution of heavier mineral phases. Examples for the latter kind of sediment component are determined in a detailed study of the Mercator MV (GoC) by high !88/86Sr ratios of 0.72 for authigenic and 0.92 ‰ for potentially extruded gypsum crystals. Combined with PW data from the other seep settings (0.2 to 0.52 ‰) a broad range of Sr contribution and fractionation processes becomes evident.

The chemical and isotopic composition of pore fluids is presented for five deep-rooted mud volcanoes aligned on a transect across the Gulf of Cadiz continental margin at water depths between 350 and 3860 m. Generally decreasing interstitial Li concentrations and Sr-87/Sr-86 ratios with increasing distance from shore are attributed to systematically changing fluid sources across the continental margin. Although highest Li concentrations at the near-shore mud volcanoes coincide with high salinities derived from dissolution of halite and late-stage evaporites, clayey, terrigenous sediments are identified as the ultimate Li source to all pore fluids investigated. Light delta Li-7 values, partly close to those of hydrothermal vent fluids (delta Li-7: +11.9 parts per thousand), indicate that Li has been mobilized during high-temperature fluid/sediment or fluid/rock interactions in the deep sub-surface. Intense leaching of terrigenous clay has led to radiogenic Sr-87/Sr-86 ratios (similar to 0.7106) in pore fluids of the near-shore mud volcanoes. In contrast, non-radiogenic Sr-87/Sr-86 ratios (similar to 0.7075) at the distal locations are attributed to admixing of a basement-derived fluid component, carrying an isotopic signature from interaction with the basaltic crust. This inference is substantiated by temperature constraints from Li isotope equilibrium calculations suggesting exchange processes at particularly high temperatures (>200 degrees C) for the least radiogenic pore fluids of the most distal location.Advective pore fluids in the off-shore reaches of the Gulf of Cadiz are influenced by successive exchange processes with both oceanic crust and terrigenous, fine-grained sediments, resulting in a chemical and isotopic signature similar to that of fluids in near-shore ridge flank hydrothermal systems. This suggests that deep-rooted mud volcanoes in the Gulf of Cadiz represent a fluid pathway intermediate between mid-ocean ridge hydrothermal vent and shallow, marginal cold seep. Due to the thicker sediment coverage and slower fluid advection rates, the overall geochemical signature is shifted towards the sediment-diagenetic signal compared to ridge flank hydrothermal environments. (C) 2009 Elsevier Ltd. All rights reserved.

The Batumi Seep Area, offshore Georgia, Black Sea, has been intensively cored (gravity cores and TV-guided multi-cores) to investigate the methane turnover in the surface sediments. The seep area is characterized by vigorous methane gas bubble emanations. Geochemical analyses show a microbial origin of the methane and a shallow fluid source. Anaerobic methane oxidation rapidly consumes the SO4 2- within the top 5-20 cm, but significant upward fluid advection is not indicated by the porewater profiles. Hence, the Batumi Seep Area must be dominated by methane gas seepage in order to explain the required CH4 flux from below. 1-D transport-reaction modelling constrains the methane flux needed to support the observed SO4 2- flux as well as the rate of near-surface hydrate formation. The model results correlate well with the hydro-acoustic backscatter intensities recorded and mapped bubble release sites using the sonar of a ROV.

[ 1] The residual dark unit of the most recent eastern Mediterranean sapropel (S1) is usually overlain by sediments with enhanced concentrations of MnO(x) in two separated layers. The variability and magnitude of the Mn enrichment at different locations and water depths indicate that Mn must have been added preferentially to sediments at intermediate ( 1 - 2 km) water depths. We propose a two-stage mechanism for the Mn enrichment that involves decreasing oxygenation with increasing water depth. This mechanism involves the loss of reduced Mn(2+) from the deepest sediments (> 2 km water depth) into overlying anoxic waters and a variable gain of MnOx in sediments in contact with oxygenated waters at shallower depth. In the S1 unit that receives the extra MnOx input, an upper higher Mn-enriched zone (> 3 wt %) is maintained continuously at the top of the accumulating S1 unit because the pore waters are anoxic at shallow sediment depth while bottom waters are oxic to some degree. In a reactive-transport model, the Mn enrichment in the upper zone could not be supported by normal sediment diagenesis. Thus the MnO(x) in the upper Mn horizon must have formed mainly in the water column. The MnO(x) in the upper Mn-enriched zone adsorbed Mo and Li from seawater in a similar manner as other Mn- enriched oxic sediments, nodules, and crusts, with a Mn: Mo ratio of similar to 600: 1, a Mn: Li ratio of similar to 750: 1, and a delta(98/95) Mo(MOMO) of - 2.5 parts per thousand.

The original geochemical signal in marine Corg-rich or formerly Corg-rich sediments is usually highly overprinted by a sequence of diagenetic processes depending on the amount of metabolizable organic carbon and the environmental conditions determining the redox potential. In general, biogenic barium can be used as a tracer for the original interval of Corg-rich sediment accumulation even when the latter has been largely removed during subsequent early diagenesis. The investigation of a range of different deep-sea sedimentary environments has shown that the detrital Ba/Al ratio is the crucial factor in the normative approach. Diagenetic processes not only result in the oxidation of organic matter but also in the remobilization of mineral phases as Mn and Fe oxides. The interrelation of a redox-horizon due to non-steady state diagenetic conditions between the last glacial and the Holocene has been reconstructed by the combination of high resolution geochemical and rock-magnetic analyses. The movement of the redox horizon led to the formation of conspicuous solid phase double peaks for Mn and Fe but also to definite anomalies in the vicinity of the redox horizon referring to dissolution of magnetic mineral phases owing to suboxic diagenesis. Such a Mn double peak feature is also known form eastern Mediterranean sapropel S1 sediments, where the double peaks had developed due to post-depositional oxygen penetration and Corg burn-down. However, the magnitudes of the upper Mn peaks are much higher (>3 wt%) within sediments from the eastern Mediterranean intermediate water depth interval (1000 to 2000 m). The change in redox conditions within the water column is responsible for this Mn-enrichment. The intermediate water depth interval preferentially gained Mn2+ that encounters oxygen and precipitates as MnOx where anoxic and oxic waters meet, whereas the Mn2+ got diagenetically lost from the deeper sediments into the anoxic bottom waters. However, the eastern Mediterranean manganese profile shapes can be diagenetically altered in areas that experienced substantial tephra or turbidite depositions such as those initiated by the Santorini explosive eruption in ~1630 B.C. This perturbation can be identified from the increased Sr/Ca and some element/Al ratio profiles. The Sr/Ca ratio, however, is not only increased in the Santorini eruption related turbidites above sapropel S1 but also in the sapropel sediments itself. This enhanced Sr/Ca ratio is associated to the enhanced Sr-rich aragonite content in the sapropel that reaches levels of up to 40 wt.% at the Sirte continental slope (northern Africa). The observed high aragonite contents could be explained by a near-costal source delivering Sr-rich aragonite skeletons or fragments thereof or by secondary diagenetic formation processes that are known to produce Sr-rich aragonite. The relationship of decreasing aragonite values with distance to the African coast and water depth has been emphasized. This relationship together with the SEM observation for the Sirte transect S1 sediments as well as the lack of variation in porosity, all point to a detrital/biogenic near-coastal source for the Sr-rich aragonite needles rather than a diagenetic one.

METEOR-Berichte