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: 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: 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: 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: 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: 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.

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: 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.