ALBERT

Description: Within the Jeddah Transect Project, a multidisciplinary marine sampling program has been performed on RV Poseidon (P408 cruise) offshore Saudi-Arabia (Red Sea). The sampling program involved three projects (http://www.ifm-geomar.de/index.php?id=jeddahtransectdisc&L=1), covering aspects of marine petrology, biogeochemistry, oceanography and biology.

Description: Cruise Report POS493 (AUV DeDAVE) – Canary Islands, January 26th to February 1st, 2016 - Test cruise for AUV “DeDAvE” around the Canary Islands

Description: Expedition M143 is a replacement for the originally scheduled expedition to the Marmara Sea to retrieve long term monitoring geodetic equipment. A short proposal to extend bathymetric mapping and imaging of active gas seepage in the Danube Delta region was approved and permission to operate in Romanian waters was successfully secured. Based on the results of mapping completed during the previous expedition M142 and other earlier missions to the same region, a set of survey lines and imaging targets were defined for M143. Objectives for expedition M143 were twofold and include the of use a dedicated 38 kHz single beam echo sounder installed in the moonpool of the research vessel METEOR for gas emission quantification and to complete bathymetric mapping for the detection of sub marine slope failures and mass transport deposits in associated with gas seepage and the occurrence of gas hydrates. During the active data acquisition phase of expedition M143 (December 12 to December 17, 2017) three sub-regions for gas flare imaging were visited (Lander Site from M142, S2 channel eastern flank, and shallow shelf region). A total of 1,189 line kilometers (642 nautical miles) of data were acquired. Out of these, a total of 238 km were acquired using the 38 kHz EK80 and EM710 (and partially EM122) multibeam data. Also, a full calibration of the 38 kHz echo sounder was accomplished and sound velocity data were recorded at the Lander and shallow shelf region survey sites. Bathymetric mapping using both EM systems EM122 and EM710 combined with the PARASOUND sub bottom profiler was completed in two main regions filling in data gaps in the existing multibeam coverage prior to M143. The first region was visited during the initial transit to the study region (December 14) around the region of the S2 channel head in water depths ~120 m. Here, a set of six parallel lines were acquired, totaling 70 km line lengths and covering an area of 11.5 square kilometers. The second region was in the eastern part of the Danube delta region, close to the Ukrainian border. In total 805 line kilometers and 472 square kilometers of multibeam data were acquired.

Description: The DRIVE (Diurnal and RegIonal Variability of Halogen Emissions) campaign to the eastern tropical North Atlantic Ocean and the upwelling off Mauritania (NW Africa) was funded by the BMBF as part of the German SOLAS project SOPRAN II (Surface Ocean Processes in the Anthropocene; www.sopran.pangaea.de): The second leg of the 399th cruise of R/V Poseidon (P399/2) took place from 31 May to 17 June 2010 (Las Palmas-Mindelo (Cape Verde Islands) – Mauritanian upwelling – Las Palmas). It was followed by the transit leg 3 (P399/3) which took place from 18 June to 24 June 2010 (Las Palmas – Vigo (Spain)) with only one stop at ESTOC. Ten scientists from IFM-GEOMAR (Kiel), IfAM (U Kiel), IfBM (U Hamburg) and IUP (U Heidelberg) representing various SOPRAN II subprojects took part in the cruise which was the sixth of a series of German SOLAS cruises to the tropical North Atlantic Ocean. The major objective of P399/2 was to investigate the regional and diurnal atmospheric and oceanic variations of halogenated compounds in the eastern tropical North Atlantic Ocean with a special focus on the Mauritanian upwelling. The main working packages of P399/2 and P399/3 included measurements of - Atmospheric BrO and IO - Atmospheric halocarbons - Other atmospheric trace gases such as ozone, methane etc. - Aerosol composition - Vertical structure of the atmosphere - Dissolved halocarbons, nitrous oxide and carbon dioxide - CTD, dissolved nutrients, O2, and chlorophyll - Microstructure of the upper water column Besides an extensive underway measurement program of dissolved (halocarbons, N2O, CO2) and atmospheric (BrO, halocarbons, other trace gases, aerosol) compounds, six 24h stations were performed and 23 regular CTD stations with depth profiles covering the entire water column were occupied.

Description: In the marine environment elevated electrical conductivities may be caused by sulfide mineralizations within the seafloor as well as hot saline pore fluids. Such conductive targets may be studied with suitable electromagnetic systems like the novel coil-system MARTEMIS1, which we previously used to investigate a known zone of sediment covered mineralization at the Palinuro Seamount (cruises POS483 & POS509) and in the vicinity of the TAG hydrothermal mound at the Mid Atlantic Ridge (cruise JC138). Both the Palinuro site as well as the sites in the vicinity of the TAG hydrothermal mound (Shinkai, Double Mound, MIR) are hydrothermally inactive and, thus, allowed to study, how the responses of an inductive EM system is influenced and shaped by mineralizations within the seafloor without having to consider the effect of of heated pore fluids. In the interpretation of the collected data at these inactive sites we learned that the MARTEMIS system is able to detect conductivity anomalies in the vicinity of mineralizations. (...)

Description: The majority of M〉8.5 active plate boundary earthquakes has hypocenters located beneath the oceans in subduction zones. Post-hoc analysis shows that most of the surface deformation related to co-seismic stress release takes place on the seafloor, in many cases unleashing major tsunamis. The structure and morphology of the seafloor and shallow subbottom thus stores crucial information on sub-seafloor processes, such as permanent deformation by seismic slip or aseismic creep within the overriding plate and earthquake and tsunami generation. We have mapped the seafloor seaward of the Northern Chilean coast between about 19°S and 22°S down to the Northern Chile deep sea trench, using the ship-based Multibeam Echosounder EM122, Parasound, and AUV (autonomous underwater vehicle) – in selected subareas - at sufficient resolution to identify active tectonic fault structures and submarine mass wasting structures, to quantitatively assess young and active deformation of the overriding plate in the area, and quantify the extent of recent catastrophic downslope mass movements of sediment. Furthermore, the investigations serve as a site survey for the deployment of the GeoSEA seafloor geodetic array, to be installed immediately after completion of this cruise. The investigations were made timely by the 1st April 2014 Pisagua M=8.2 earthquake, that ruptured the plate interface in the northern part of the area of investigation. The central and southern parts are located in the last remaining locked seimotectonic segment along the Chilean active margin. In addition to providing the first data base for geomorphological and tectonic interpretation of geo-processes at the seafloor, the bathymetric mapping done during SO244 Leg 1 will provide an important data reference for possible post-earthquake surveys once this seismotectonic segment will have broken in the future.

Description: At present, investigations of submarine massive sulfides (SMS) are mostly limited to active systems due to the available methods and technologies, which rely on the detection of water column anomalies (tempera - ture or chemical tracers) and the study of seafloor's morphology. They fail to detect sites where hydrothermal activity has ceased and former landmarks such as black smokers have been eroded or are covered by sediments. During RV Poseidon cruises POS483 (“ElectroPal”) and POS484 (”MARSITE”) we have successfully collected EM and airgun seismic data over an inactive and sediment covered SMS site at Palinuro, which had previously been found by chance in 1986 and was drilled to 5m depth during research cruise M73/2. EM measurements, carried out with the novel system MARTEMIS1, not only showed high conductivities in the vicinity of the SMS deposit, but also revealed a second anomaly, possibly a zone of buried mineralization at greater depth. During cruise POS509 previous measurements were continued and extended to get a full areal coverage of the structure to fully delineate and characterize the SMS sites. EM investigations were accompanied by measurements of the ambient electrical field (→ selfpotential (SP)) and additional geophysical (heat probe) and geological (gravity core) measurements for ground truthing and further structural insight. The combination of experiments proved to be convenient in terms of handling on the ship, as EM experiments on the one hand and measurements with heat probe and gravity coring on the other hand were performed in an alternating manner each other day. This alternating style of experiments gave each method time for adjust - ments and repairs as well as time to take a first look at results so that following investigations could be directly aimed at a specific target. As an example, an anomaly detected in the SP measurements in the NNW was used to guide the last gravity coring, which then found sulfide muds in an area where sulfides were previously not expected.

Description: Poseidon cruise 518 (leg 1 and 2) took place in the framework of the Horizon 2020 project STEMM-CCS of the EU. The project’s main goal is to develop and test strategies and technologies for the monitoring of subseafloor CO2 storage operations. In this context a small research-scale CO2 gas release experiment is planned for 2019 in the vicinity of the Goldeneye platform located in the British EEZ (central North Sea). Cruise POS518 aimed at collecting necessary oceanographic and biogeochemical baseline data for this release experiment. During Leg 1 ROV PHOCA was used to deploy MPI’s tool for high-precision measurements of O2, CO2 and pH in the bottom water at Goldeneye. In addition, ROV push cores and gravity cores were collected in the area for sediment biogeochemical analyses, and video-CTD casts were conducted to study the water column chemistry. The stereo-camera system and a horizontally looking multibeam echosounder, both, for determining gas bubble emissions at the seafloor were deployed at the Figge Maar blowout crater in the German Bight. Investigations were complemented by hydroacoustic surveys detecting gas bubble leakages at several abandoned wells in the North Sea as well as the Figge Maar. Surface water alkalinity as well as CH4, CO2, and water partial pressures in the air above the sea surface were measured continuously during the cruise. During Leg 2 three different benthic lander systems were deployed to obtain baseline data of oceanographic and biogeochemical parameters for a small research-scale CO2 gas release experiment planned for 2019. The first lander was equipped with an acoustic Doppler current profiler (ADCP), a CTD and an O2 optode. It was deployed for 6 days close to Goldeneye to obtain high resolution data which can be linked to the long-term measurements of the NOC-Lander. This lander is equipped with a suite of sensors to monitor temperature, conductivity, pressure, current speed and direction, hydro-acoustic, pH, pCO2, O2 and nutrients over a period of about 10 months with popup telemetry units for data transmission via IRIDIUM satellite telemetry every 3 months. Two short-term deployments of the Biogeochemical Observatory (BIGO) were conducted to study the molar ratio between oxygen and CO2-fluxes at the seafloor. Sediment cores obtained by gravity and multi corer were collected for sediment biogeochemical analyses and video-CTD casts were used to study the chemistry of the water column.

Description: Cruise WND-V was the fifth and final expedition of the West Nile Delta project carried out at IFM-GEOMAR with support from RWE-Dea. On this concluding cruise of the project, the two mud volcanoes North Alex and Giza were once again visited, this time using the Greek R/V AEGAEO. The primary purpose of the WND-V cruise was the recovery of instruments and observatories which had been deployed in or near the active centers of North Alex and Giza MVs over the past 30 months. In addition, complementary new data were acquired that were needed to better quantify the methane flux from the centers of both MVs. From 15 to 25 June 2010, the following activities were carried out: · recovery of 12 long-term Ocean-Bottom-Seismometers (OBS) at North Alex MV, which had been deployed during POSEIDON cruise P388 in 2009. · recovery of 4 instruments for measuring long-term pore pressure variations (piezometers) on the slope near North Alex MV, deployed during POSEIDON cruise P388 in 2009. · recovery of 6 instruments for measuring long-term chemical flux (CATmeters) at Giza and North Alex MV. · recovery of 1 instrument (OBMets) for measuring methane flux from the seafloor at North Alex MV. · recovery of 2 tiltmeters for measuring seafloor deformation at North Alex MV. · recovery of 2 long-term temperature observatories at Giza and North Alex MV. · CTD casts in the central area of North Alex MV · Imaging of bubble streams from the active center of North Alex using an SIMRAD EK60 sonar system. Although hampered by poor weather during the final days of the cruise the recovery operations were finished two days earlier than expected. Bathymetric data acquisition however, which had been part of the original schedule had to be cancelled due to bad weather as well as technical problems with the deep water sonar systems.

Description: The evolution from the Western Mediterranean Sea is inherently governed by (i) plate convergence between Nubia (Africa) / Eurasia and (ii) subduction related slab-roll back. Both processes are responsible for the surface features / topography of the Gulf of Cadiz / Gibraltar Arc / Alboran Sea / Rif / Betic domain and deep-seated features related to the consumption of African lithosphere. The project is part of the ESF-EUROCORES programme TOPO-EUROPE and is aiming to study the interrelation between convergence and major tectonic fault zones in the Gulf of Cadiz and the Alboran Sea (Trans-Alboran- Shear-Zone – Alboran Ridge) and Miocene subduction / deep-seated seismicity at 40-150 km depth. Monitoring networks with ocean bottom seismometers (OBS) and hydrophones (OBH) were installed first in the Alboran Sea (August 2009 to January 2010) and later in the Gulf of Cadiz (January 2010 to July 2010), providing for the first time local earthquake data collected on ocean bottom stations. First results suggest that the collected data are of every good quality to assess seismotectonics in both domains and yielding travel time data for unique tomographic images of the Gibraltar arc area and Alboran domain, providing seismic constraints on the structure of crust and mantle.

Description: R/V SONNE cruise SO-233 WALVIS II conducted geological, morphological, and biological studies in the area of the aseismic Walvis Ridge and the adjacent ocean floor (South Atlantic). The Walvis Ridge is a textbook example of a hotspot track connected to a continental flood basalt province and represents the Atlantic “type locality” for the enriched mantle one (EM-I) geochemical endmember in intraplate volcanic rocks. Despite its importance in the global hotspot reference frame, endmember geochemical composition, and uncertainties in its formation and evolution, basement sampling of the Walvis Ridge remained poor to date, in particular along its easternmost 1500 km. The geological studies carried out during SO-233 therefore aimed for extensive multi-beam mapping using a SIMRAD EM 120 echo-sounding system, sediment echo-sounding using a ATLAS PARASOUND sub-bottom profiling system, and hard rock sampling by dredging and TV-grab of the Walvis Ridge and associated features. The major targets of the WALVIS II project are (1) to test for age progressive volcanism along the ridge, (2) to differentiate between classical hotspot and plate fracturing models for its formation, and (3) to constrain the origin, temporal and spatial evolution of melting conditions and source compositions (in particular regarding the EM-I endmember and proposed zonation models of mantle plumes). The biology program conducted on SO-233 comprised sampling of benthic organisms and meiofauna using a TV-multi-corer, a TV-grab, sediment traps installed in the geological dredges, and by collecting marine invertebrates from the hard rocks yielded by dredging. The biological investigations of the WALVIS II project intend to describe the benthic diversity of deep-sea invertebrates of the Walvis Ridge and will help to identify proxies of species connectivity and dispersal between the Walvis Ridge and neighboring ridge like structures (e.g. Agulhas Ridge). Another objective is to test whether connectivity of benthic communities in the Angola and Cape Basins is interrupted by the Walvis Ridge. SO-233 multi-beam mapping revealed that the southern bifurcated section of the Walvis Ridge appears to have formed through the coalescence of former volcanic islands. The new bathymetric data also yielded several evidence for large-scale extensional tectonic movements which are most likely related to the separation of the Walvis Ridge and Rio Grande Rise that were rifted apart by the mid Atlantic Ridge. Seventy-one dredge hauls have been conducted during SO-233. Of these, 28 delivered massive lavas, 24 volcaniclastic rocks including breccias containing lava fragments, 22 sedimentary rocks, and 11 Mn-Fe-oxide crusts and nodules. The volcanic rocks comprise a broad variety of lavas as well as epiclastic, hydroclastic, and pyroclastic rocks. Carbonates dominate among the non-volcanic rocks, many of them represent relicts of fossil coral reefs. Despite technical problems with the EM 120 system and difficult weather and seafloor conditions occasionally constraining rock sampling, SO-233 achieved its major goals, i.e. bathymetric mapping and representative hard rock sampling of all major geomorphological units of the Walvis Ridge and of associated features. The set of rock samples recovered during SO-233 represents the by far most detailed sampling of the Walvis Ridge to date. Out of 91 collecting stations, 80 stations yielded the total amount of 80 kg of sediment from sediment traps in the geological dredges, TV-multi-corer tubes and TV-grab. At 44 stations we could collect macrofaunal organisms, partly in large quantities. Ninety specimens of living brachiopods representing 6 genera were found at all depths and will mainly be used for molecular diversity studies. The remaining living macrofauna was largely composed of sponges, octocorals, some deep water hexacorals, molluscs, polychaetes, bryozoans, cirriped crustaceans and a few isopods and amphipods, mainly occurring in small numbers and medium diversity. The most spectacular finding was a fossil cold water reef mound community, which shows similarities in species composition to North Atlantic cold water reefs and proofs the influence of Antarctic benthos communities on the Walvis Ridge fauna mediated by northbound cold water currents. The samples represent the most diverse collection of benthos organisms ever retrieved from the Walvis Ridge region.

Description: R/V POSEIDON cruise P457 aimed further development of detailed marine tephrochronology of Iceland by sediment coring in order to improve our knowledge of the spatio-temporal evolution of Icelandic volcanism and related hazards. In addition, the marine record contains paleoclimatic information, which may relate recurrent glacier advances and land degradation periods to ocean and atmospheric circulation changes. A minor sub-project should contribute to a better understanding of Surtsey volcanism by investigations of marine Surtsey tephra. P457 conducted extensive sediment echosounding (11 surveys with a total length of c. 425 nm) in order to identify undisturbed sediment sequences for coring. At 20 appropriate sites, P457 deployed gravity and/or gaint box corers to recover ultra-high resolution sediment cores from 〈 100 m to ~1,600 m water depth at the south-western, southern and eastern sectors of the Icelandic shelf and slope. Of these deployments, 9 gravity corers yielded altogether 59.5 m core recovery and 11 box corers recovered surface sediment samples. Additionally 7 CTD/rosette water sampling stations have been performed at shallow sites close to Iceland and at deep sites further offshore in order to determine the REE distributions and the Nd and Hf isotope compositions of the sea water. No equipment was lost or significantly damaged. Cruise P457 was particularly successful in the working areas southwest and south of Iceland but failed to recover long sediment cores in the eastern working areas and at Surtsey. Sand, clayey silt, clayey sandy silt, sandy clayey silt, and volcanic ashes are the dominant lithologies in the P457 sediment cores. Preliminary studies of selected sedimentary records along the Iceland margin from ca. 24°W to 12°W on both sides of Reykjanes Ridge suggest that a correlation of these cores is possible, implying that sedimentary records are undisturbed and of high quality. Notably, distinct volcanic ash layers can apparently be traced in the P457 cores across the working area. Preliminary age models of selected cores show that the sedimentation rates around Iceland are low with only a thin Holocene. Sediment records cover approximately 120.000 years at most.

Description: RV Sonne cruise 206 started on the 31st of May in Caldera (Costa Rica) and ended there on the 18th of June 2010. An international group of 23 scientists and 2 guests from Costa Rica set out to perform geophysical, biogeochemical, and sedimentological investigations at and around a number of submarine cold seeps that are ubiquitous along this convergent continental margin. The cruise was predominantly conducted as a pre-site survey for IODP (proposal 633Full-2; Costa Rica Mounds) in order to fill existing gaps in the seismic record at two of the proposed drill locations. A 2D seismic survey was conducted running over the large-scale seamount subduction slide “Jaco Scarp” yielding a highly improved image of the structural pattern within the upper 1000 m of the sedimentary sequence. In addition, high-resolution 3D seismic data, roughly covering the uppermost 300 m, could be obtained in the Mound 11/12 area, which will allow for a detailed analysis of the internal structure of these mud volcano-like features and help to understand the complex relation to the upward directed material flow. Moreover, a total number of 36 sediment cores (TV-guided multicorer, gravity corer) were successfully retrieved from active cold seeps and submarine slides and a large number of sub-samples were taken for subsequent geochemical and microbiological analyses. Overall, all major tasks of this cruise could successfully be fulfilled and the results will help to further our understanding of mechanisms controlling fluid flow in the deep subsurface of active continental margins.

Description: Cruise P453 & P458 with R/V POSEIDON aim to conduct 3D wide-angle ocean bottom recording (OBR) data during the acquisition of 3D multichannel seismic (MCS) reflection data (D. Sawyer, Rice University & T.J. Reston, Birmingham) and to analyze and interpret a highresolution densely sampled 2D OBR wide-angle profile. The primary goal of the wide-angle data will be to provide an accurate and detailed 3D P-wave velocity model for the 3D reflection data. Particularly the densely sampled 2D profile will help to determine the degree of thinning within the crust and the degree of serpentinisation of the uppermost mantle. The collection of 3D MCS data gives the unique opportunity to obtain densely sampled water column reflection data and to analyze spatial and temporal (4D) variations of the internal wave field which will yield new understanding and insights into water mass mixing processes offshore west Iberia. Contemporaneously hydrographic data will be collected to calibrate and analyze the oceanic thermohaline structures originating from the interaction between Atlantic waters and the Mediterranean Sea Outflow.

Description: The R/V SONNE expedition SO265 is the central activity of the research project "Shatsky Evolution" that is funded by the Federal Ministry of Education and Research and conducted by the GEOMAR Helmholtz Centre for Ocean Research Kiel in collaboration with international partners. The goal of the project is the investigation of the late stage evolution of Shatsky Rise, a vast, submarine volcanic plateau (Large Igneous Province) in the northwest Pacific. In particular, the project aims to investigate the transition from plateau volcanism (the main body of Shatsky Rise) to postulated hotspot track volcanism (Papanin Ridge and/or Ojin Rise seamounts). Applied methods included bathymetric mapping with the ship's own multi-beam echosounder (KONGSBERG EM 122), subbottom profiling (ATLAS PARASOUND DS P70), and rock sampling with chain bag dredges. The main working areas were the Papanin Ridge (the northern extension of Shatsky Rise) and the Ojin Rise Seamount Province (a broad belt of individual seamounts to the east of Shatsky Rise). Dredge hauls were conducted between ~36°N and ~44°N and ~163°E and ~170°E covering the entire geographic extent of both working areas. A third working area, the northern part of Shatsky Rise dominated by its Shirshov Massif, served as a contingency area and only a few dredge hauls were conducted there. In addition, sampling was successfully executed at Hokkaido Trough (45°06'N, 162°27'E), located ~320 km northwest of Papanin Ridge. A total of 72 dredge hauls in average water depths of 4,640 m were carried out during SO265. Of these, 49 (= 68%) delivered in situ volcanic rocks samples. No deployed equipment was lost or damaged. Post-cruise investigations at GEOMAR and cooperating institutions will include volcanological/petrological, geochronological, and geochemical studies. Furthermore, macro-benthic organisms were collected from the surfaces of the recovered rocks to study the diversity of deep-see invertebrates, and sediment sampling (by small sediment traps installed in the dredges) was conducted for meiofauna studies.

Description: Cruise SO210 with RV SONNE to the active continental margin off Chile was conducted by shiptime exchange with RV METEOR. Funds for mobilizing the research team were provided by the German Science Foundation (DFG) in conjunction with the Collaborative Research Centre (SFB) 574 of the University of Kiel. In the first years, the SFB 574 investigated the pathways and fluxes of volatiles through the erosive subduction zone off Central America. For comparison, the studies were extended to the accretionary margin off Central Chile. Cruise SO210 is the last cruise conducted in the framework of SFB 574 and based on investigations of previous SFB-cruises on the RVs VIDAL GORMAZ and JAMES COOK. The first leg of cruise SO210 was dedicated to long gravity coring for volcanic ash layers from the erruptive Southern Volcanic Zone (SVZ) of the Andes that were either deposited as fallouts onto the incoming Nazca Plate or transported down the slope and across the Chile Trench. Eight gravity cores of 12 m length were retrieved seaward of the Chile Channel on the outer rise of the Nazca Plate. The second goal for coring was the description and dating of previously mapped submarine landslides as well as retrieval of slide-related material for geo-technical experiments. As the deployment frame for long coring had to be removed on the second leg we continued coring for mass-wasting and geochemistry with short cores. Ten gravity cores of 3 or 6 m barrel length were retrieved upslope of slides, the glide plane and redeposited material downslope of the slide evacuation area. This sampling activity was supported by detailed acoustic surveys with Parasound and multibeam to remap critical areas for mass wasting in search for events, e.g. triggered by the recent Mw 8.8 Maule Earthquake, such as flanks of submarine canyons or previously detected submarine slides and to fill data gaps in the existing bathymetric data. The major activity of the entire cruise was dedicated to the search and detailed sampling of manifestations of fluid discharge activity on the Chilean forearc. A total of 11 deployments with the video sled OFOS and 12 dives by the ROV KIEL 6000 were conducted for ground-truthing of information which indicated possible seep activity and has been obtained during previous cruises to the Chilean forearc. In five working areas we found manifestations of fluid discharge. In these areas the survey was followed by an intense sampling of bottom water, sediments, carbonates, mega and meiofauna and the deployment of instrumentation on the seafloor. The goal of these deployments was to measure in situ seabed methane emission rates and associated fluxes of sulfide and major electron acceptors such as oxygen at seep sites along the Chilean margin and to understand its controls. This was accompanied by CTD casts to trace oxygen and the fate of methane discharge in the water column. Sediment cores obtained by multicorer or ROV were used for the geochemical characterization of the pore water and microbiological studies which include turnover rate measurements, molecular studies, flow through experiments and sampling of active sediments. Authigenic carbonates obtained by TV-Grab or ROV were sampled for fauna, biomarker studies and investigations to reconstruct the growth structures, calcification processes and fluid-pathway systematic. The sampling of sediments and carbonates recovered a unique fauna with 79 different taxa, several of them appear to be species new to science.

Description: Cruise SO-214 of R/V SONNE headed by IFM-GEOMAR served two legs of project NEMESYS, funded through the German Ministry of Education and Research (BMBF). Major partners of the project are Leibniz Institute of Marine Science (IFM-GEOMAR) and the Federal Institute of Geosciences and Natural Resources (BGR) Germany, as well as the Institute of Geological and Nuclear Sciences (GNS) and the Royal Netherlands Institute for Sea Research (NIOZ). NEMESYS aims to extend understanding and modelling of cold vents along the Hikurangi Margin (HM) off the east coast of the North Island of New Zealand. Since the first findings in the late 80´s several cruises have been dedicated to map and investigate the active seepage of Methane in this area. Results of these cruises headed by New Zealand and international scientists provided the database for the first joint German – New Zealand expedition SO-191 in 2007. During this cruise with R/V SONNE the HM was investigated within three legs comprising all marine geo-scientific disciplines. The major findings in geophysical, geological, geo-chemical, and biological research were published in a special issue by Marine Geology (Vol. 272, 2010). Nevertheless a lot of questions remained or were raised by the upcoming results. Still lateral continuation of feeder channels and a possible relation between internal structure, activity and tectonic regime of a seep site were not understood. The geological, geo-chemical and biological analysis has been related to the overall description and study of the seep sites along the margin. Detailed studies across a seep site and high-resolution sampling to study the internal variation of Methane production and the influences to chemistry and habitat have not been complete with the required intensity. These exemplary listed investigations together with an additional list of questions to seepage led to the follow-up project SO-214 NEMESYS, which was funded through the German Ministry of Education and Research (BMBF). Aim of the project NEMESYS is to confirm derived models of seep structures and to extend the existing database and knowledge by high-resolution sampling in all disciplines. Based on the findings of the SO-191 New Vents project Opouawe Bank and Omakere Ridge were identified as the areas with the highest interest for our additional studies. Opouawe Bank provides a high density of active seep sites with various expressions of feeder channels in seismic images. Omakere did provide the only seep sites that were found without feeder channels underneath. In between the Porangahau Ridge was selected as third target due to the indications of either gas or hydrate formation without active gas expulsion. Cruise SO-214 with R/V SONNE was split into two legs. The seismic part started on 09th March 2011 in the port of Wellington. Two 3D seismic cubes were acquired above active seep sites at Omakere and Opouawe Bank. A third cube at Porangahau Ridge could not be completed due to technical problems with the equipment and rough weather conditions. Intensive Parasound Profiling and extended 2D seismic with high resolution (up to 1.2 m migration grid) were undertaken. Many more feeder channels were identified than previously known from the SO-191 data, although not all of them terminate in a seafloor expression. The second leg left the port of Wellington on 6th April 2011 dedicated to intensive geological, geo-chemical and biological investigations. The major work was completed at Opouawe Bank. Based on images of the seismic data compilation North and South Tower seeps and seep site Takahe were chosen for the intensive sampling program. CTD and gravity cores were taken in dense spacing to investigate the local interaction of seepage and surrounding seafloor and water column. The water column showed limited stratification but seemed to be influenced from stormy weather. Biologic investigations showed limited variations compared with the SO-191 expedition, mainly in the distribution of fauna. The variety of amphipods seems to be a unique feature of the NZ seeps. The second leg suffered from bad weather conditions, which anticipated work during 100 hrs. out of scheduled 330 hrs. All meta data of the cruise are available through the IFM-GEOMAR Data Management Portal (https://portal.ifm-geomar.de/web/guest/home)

Description: The cooperative research project between Chinese and German leading marine research institutions, the Guangzhou Marine Geological Survey (GMGS) and Leibniz-Institut für Meereswissenschaften Kiel (IFM-GEOMAR) addressed the geological methane budget and environmental effects of methane emissions from gas hydrates along the passive margin of the northern South China Sea. Two areas were surveyed of which the NE area (A) was sampled in great detail, whereas area B, after an initial survey, yielded less promising results. Swath map bathymetry, ocean floor observation by continuous video survey (OFOS) and water column methane distribution pattern provided the basis for locating several sites of ongoing methane venting. Outstanding among these was a methane-derived carbonate structure in water depths of 600-900m. Vast accumulations of vent carbonate debris, pavements and edifices standing above the seafloor characterize this structure. A 30-m high edifice, named Jiu Long Methane Reef, proved to be an active cold vent site with chemosynthetic fauna and bacterial mats. At deep sites ( apprx. 3000m) in and adjacent to the Formosa Canyon methane anomalies in the bottom water and clam colonies also indicate active methane venting. Pore water and gas chemistry on gravity cores indicated rather shallow depths of the sulfate-methane-interface (SMI) and documented chloride anomalies. High methane concentrations (exceeding 10.000 μM) in sediments, which when extrapolated, suggest that saturation might be reached at about 16-24 mbsf at which depths the shallowest gas hydrates might be encountered in the area. The project results contribute directly to several major science policy missions. (1) Documentation of vast amounts of methane emmited from the passive margin of the northern South China Sea is seen as evidence for long-term climate forcing by the greenhouse gas methane. (2) The functioning and significance of deep-sea biota as modulating the greenhouse gas budget is convincingly demonstrated by the vast amounts of methane carbon fixed as authigenic carbonates. (3) Further development of TV-guided deep-sea instrumentation, and above all the retrieval of undecompressed sediments, have again been deomonstrated as high a priority topic for the future of marine science. (4) The success of the project has demonstrated how international partnerships can efficiently been implemented.

Description: The R/V SONNE expedition SO-249 is part of the research project BERING, conducted in the framework of the Russian-German Agreement on Marine and Polar Research and in close cooperation with U.S. American colleagues. The overarching goal of BERING is to elucidate the magmatic and tectonic evolution of the Bering Sea and its margins over the past ≥50 m.y. In particular, BERING investigates the physical and chemical conditions that control the development of subduction zones, including subduction initiation, evolution of mature arc systems, and the impact of subduction volcanism on the environment. R/V SONNE cruise SO- 249 BERING conducted geological, morphological, and biological studies in the in western the Aleutians, the Pacific seafloor subducting beneath the Aleutians and northern Kamchatka, and in the western Bering Sea. Besides extensive multi-beam mapping and sediment echo-sounder profiling, total of 150 dredge hauls have been conducted on the two legs of cruise SO-249. Of these, 91 delivered massive magmatic and/or metamorphic rocks, 34 volcaniclastic rocks including breccias containing lava fragments, 64 sedimentary rocks, and 19 Mn-Fe-Oxide crusts and nodules. No equipment was lost or seriously damaged. SO-249 achieved its major goals and the SO-249 sample set represents the most detailed sampling of the working areas to date. The on shore work program at Russian, German, and U.S.-American institutions includes geochronological, petrological and geochemical studies on igneous samples obtained during the cruise. The results of BERING will be integrated with those of previous campaigns (e.g. KOMEX, KALMAR), and work carried out within the World Oceans and GeoPRISMS initiatives. The main goal of biological sampling was to survey the benthic biodiversity in the study area. In addition, fresh specimens pertaining to specific taxa (Cnidaria, Brachiopoda, Cephalopoda, Echinodermata) were collected to supplement ongoing research projects. Of the 150 dredges taken, 150 (100%) contained sediment and 112 (74.7%) contained macrofauna. In addition to the 150 sediment samples, almost 1,500 single benthic, benthopelagic, and pelagic macrofaunal organisms were obtained. The majority of the objectives of biological sampling were reached, in particular with regard to obtaining fresh tissue for immunohistochemical, genomic, and transcriptomic analysis from various brachiopod and ophiuroid species.

Description: The research project SO208 PLUMEFLUX (Propagation of Galápagos Plume Material in the Equatorial East Pacific) is funded by the German Ministry of Education and Research (BMBF) and focusses on seamounts on the Cocos Plate, formed at the East Pacific Rise but presently located off the coast of NW Costa Rica and Nicaragua (Leg 1), and on the Cocos-Nazca-Spreading Center(CNS; Leg 2). The studies conducted on cruise SO208 included multi-beam mapping, sediment echo sounding, hard rock sampling, as well as sedimentological and biological sampling. The major geological targets of Leg 1 were (1) to evaluate if the seamounts off northern Costa Rica and Nicaragua were formed by the Galápagos hotspot and thus to constrain the extent of influence by the Galápagos plume on the upper asthenosphere and lithosphere and (2) to constrain better the material input into the Central American subduction zone. Leg 2 aimed to sample profiles of the seafloor perpendicular to the CNS using the mobile drill Rockdrill 2 of the British Geological Survey, in order to reconstruct plume-ridge interaction in the past to complement morphological, petrological and geochemical studies carried out on previous cruises along the ridge axis (e.g. SO158). The integration of the results with existing data should contribute towards a better understanding of transport processes of plume material in the upper mantle and of the geodynamic evolution of the central East Pacific. The sedimentological studies carried out on both Legs of SO208 focussed on radiolarian assemblages. SO208 startet in Caldera/Costa Rica on July 15th, 2010, and ended in Guayaquil/Ecuador on August 29th, 2010. During Leg 1 nineteen seamounts on the Cocos Plate have been mapped and sampled. Within only 12 days at sea, a total of 41 stations(28 dredges, 2 TV grabs, and 11 multicorers) were carried out. Of these deployments, 23 recovered magmatic rocks, 15 volcaniclastics, and 13 Mn-Fe oxides. The samples comprise mainly pillow and sheet lavas, often with fresh glassy margins, and a wide spectrum of volcaniclastic rocks. Notably, we found several indications for explosive volcanic activity at water depths 〉 3,000 m. Due to a series of unfortunate circumstances beyond our control, the planned Rockdrill 2 deployment on Leg 2 had to be cancelled. Instead we mapped and collected samples via dredging from 60 localities along five profiles perpendicular to CNS. A total of 83 stations (76 dredges, 3 TVgrabs, and 4 multicorers) were carried out. Of these deployments, 59 recovered magmatic rocks, 3 volcaniclastics, 51 volcanic glass, and 6 Mn-Fe oxides, making this a successful cruise despite the Rockdrill problem. The first and most detailed profile (with 23 sampled localities) extended from the ridge axis to the north at ~92°W. The morphology shows alternating regions of abyssal ridges and valleys (possibly reflecting less plume input into the ridge) and thicker elevated bands commonly containing seamounts, some of which are tectonically deformed (possibly reflecting axial ridge type morphology and thus greater plume input into the ridge). The second profile was carried out at the shallowest part of the ridge axis, closest to the hotspot, just to the east of the 91° Transform Fault. The third profile extended 30 km north of the ridge (at ~89°30´W), where a formerly on-axis seamount has been split in half. We want to evaluate how far in the past the unique enriched geochemical anomaly associated with the seamount persisted in the past. Thirteen sites were successfully sampled along a fourth profile at 89°10’W, extending 35 km north and 35 km south of the CNS into crust up to 500,000 yrs old. This site was selected, because a major depleted geochemical anomaly exists at that location. A final short profile was carried out to the north and south and east (on the ridge axis) of a lava plateau at 88°20’W that represents an enriched anomaly along the ridge axis. The morphology of the area studied on Leg 2 strongly suggests that the intensity of interaction of the plume with the ridge has varied considerably over the last several hundred thousand years along the entire part of the ridge that we studied. Geochemical data should allow us to constrain better variations in plume-ridge interaction through time. Biological material was obtained successfully as macrofauna and as sediment samples containing meiofaunal organisms with the help of a geological chain bag dredge, sediment traps, a multicorer and a TV-grab. Macrofaunal organisms were recovered at 93 out of 124 stations, 37 stations revealed sediment samples. During the cruise, a total of 8,598 meiofaunal organisms were centrifuged out of about 45 kg of sediment and sorted to animal group. Foraminifera and Nematoda dominated the meiofauna, followed by Copepoda and at a lower abundance by Tardigrada, Kinorhyncha and Loricifera. We also discovered a highly diverse benthic macrofauna, mainly represented by Porifera, Bryozoa, Annelida, Brachiopoda and even a few monoplacophoran molluscs.