ALBERT

Description: The continental slopes of the Black Sea show abundant manifestations of gas seepage in water depth of

Description: Among the worldwide expeditions conducted with German research vessels (RVs), an enormous amount of hydro-acoustic data, especially bathymetry, is acquired. Since 1995, the BSH (German Federal Maritime and Hydrographic Agency) is collecting bathymetric datasets, mainly from the RVs METEOR, M.S.MERIAN & SONNE. The institute built up a static website (http://www.bsh.de/de/Meeresdaten/Seevermessung_und_Wracksuche/Bathymetrie/index.jsp) that allows reviewing all the track lines of the research vessels where data is available. Although mandatory, some of the datasets never reached BSH. Upon request, the accessible data will be available for download via FTP from the BSH web-portal. For a more contemporary and sustainable approach in accessing bathymetric metadata and data of all German research vessels, we created a bathymetry showcase within the MaNIDA project (2011/2-2014; http://www.manida.org/) and the resulting “Data Portal German Marine Research” (http://manida.awi.de/). A PostGIS database based on the ISO 19139-2:2012 standard was set up and a solitaire frontend-GUI developed, which allows ingestion of cruise metadata and the automatic acquisition of hydro-acoustic metadata on the entity level (per recorded raw data survey-line). In parallel, the dataset will be archived in PANGAEA (https://www.pangaea.de/) and metadata then completed with the link to the stored dataset. The Bathy-Meta-Database and its services run as a surplus-portal of PANGAEA. This development lead to our participation of the EMODnet Bathymetry Project (http://portal.emodnet-bathymetry.eu/) where metadata is shown for every grid-cell of the compilation of bathymetric datasets while an adapted, world-wide GEBCO dataset (http://www.gebco.net/) fills the gaps across the European seas. The most recent development deals with retrieving metadata from processed bathymetry, based on further software development and the utilization of the open-source suite MB-System (http://www.mbari.org/products/research-software/mb-system/), which concatenates the long-term storage of raw & processed bathymetry in PANGAEA.

Description: The continental slopes of the Black Sea show abundant manifestations of gas seepage in water depth of 〈720 m, but underlying controls are still not fully understood. Here, we investigate gas seepage along the Bulgarian and Romanian Black Sea margin using acoustic multibeam water column, bathymetry, backscatter, and sub-bottom profiler data to determine linkages between sub-seafloor structures, seafloor gas seeps, and gas discharge into the water column. More than 10,000 seepage sites over an area of ∼3,000 km 2 were identified. The maximum water depth of gas seepage is controlled by the onset of the structure I gas hydrate stability zone in ∼720 m depth. However, gas seepage is not randomly distributed elsewhere. We classify three factors controlling on gas seepage locations into depositional, erosional, and tectonic factors. Depositional factors are associated with regionally occurring sediment waves forming focusing effects and mass-transport deposits (MTDs) with limited sediment drape. Elongated seafloor depressions linked to faulting and gas seepage develop at the base between adjacent sediment waves. The elongated depressions become progressively wider and deeper toward shallow water depths and culminate in some locations into clusters of pockmarks. MTDs cover larger regions and level out paleo-topography. Their surface morphology results in fault-like deformation patterns of the sediment drape on top of the MTDs that is locally utilized for gas migration. Erosional factors are seen along channels and canyons as well as slope failures, where gas discharge occurs along head-scarps and ridges. Sediment that was removed by slope failures cover larger regions down-slope. Those regions are devoid of gas seepage either by forming impermeable barriers to gas migration or by removal of the formerly gas-rich sediments. Deep-rooted tectonic control on gas migration is seen in the eastern study region with wide-spread normal faulting promoting gas migration. Overall, gas seepage is widespread along the margin. Gas migration appears more vigorous in shallow waters below ∼160 m water depth, but the number of flare sites is not necessarily an indicator of the total volume of gas released.

Description: Among the worldwide expeditions conducted with German research vessels (RVs), an enormous amount of hydro-acoustic data, especially bathymetry, is acquired. Since 1995, the BSH (German Federal Maritime and Hydrographic Agency) is collecting bathymetric datasets, mainly from the RVs METEOR, M.S.MERIAN & SONNE. The institute built up a static website (http://www.bsh.de/de/Meeresdaten/Seevermessung_und_Wracksuche/Bathymetrie/index.jsp) that allows reviewing all the track lines of the research vessels where data is available. Although mandatory, some of the datasets never reached BSH. Upon request, the accessible data will be available for download via FTP from the BSH web-portal. For a more contemporary and sustainable approach in accessing bathymetric metadata and data of all German research vessels, we created a bathymetry showcase within the MaNIDA project (2011/2-2014; http://www.manida.org/) and the resulting “Data Portal German Marine Research” (http://manida.awi.de/). A PostGIS database based on the ISO 19139-2:2012 standard was set up and a solitaire frontend-GUI developed, which allows ingestion of cruise metadata and the automatic acquisition of hydro-acoustic metadata on the entity level (per recorded raw data survey-line). In parallel, the dataset will be archived in PANGAEA (https://www.pangaea.de/) and metadata then completed with the link to the stored dataset. The Bathy-Meta-Database and its services run as a surplus-portal of PANGAEA. This development lead to our participation of the EMODnet Bathymetry Project (http://portal.emodnet-bathymetry.eu/) where metadata is shown for every grid-cell of the compilation of bathymetric datasets while an adapted, world-wide GEBCO dataset (http://www.gebco.net/) fills the gaps across the European seas. The most recent development deals with retrieving metadata from processed bathymetry, based on further software development and the utilization of the open-source suite MB-System (http://www.mbari.org/products/research-software/mb-system/), which concatenates the long-term storage of raw & processed bathymetry in PANGAEA.

Description: Position, height, width, volume, base horizon and depth of the seafloor above the identified cold-water coral mounds in the seismic datasets of the Atlantic Moroccan coral province.

Description: Swath sonar bathymetry data used for that dataset was recorded during RV METEOR cruise M79/2 using Kongsberg EM 120 multibeam echosounder. The cruise took place between 26.08.2009 and 21.09.2009 in the northeastern Atlantic. The main objectives of the cruise were the analysis of the structure, dynamic and natural hazard potential of the Atlantic section of the European-African plate boundary in the area of the eastern Azores (São Miguel region) and Gloria Fault. The measurements included marine geophysical experiments like refraction and reflection seismics, potential field recordings (gravity & magnetics), parametric sediment subbottom profiling and multibeam bathymetry [DOI:10.2312/cr_m79_2]. CI Citation: Paul Wintersteller (seafloor-imaging@marum.de) as responsible party for bathymetry raw data ingest and approval. Description of the data source: During the M79/2 cruise, the hull-mounted KONGSBERG EM120 multibeam ecosounder (MBES) was utilized to perform bathymetric mapping in middle to deep water depths. Two linear transducer arrays in a Mills Cross configuration transmit acoustic signals of a nominal sonar frequency of 12 kHz. With 191 beams, the emission cone has a dimension of max. 140° across track and 1° along track. With a reception obtained from 288 beams, the actual beam footprint is 1° by 2°. Depending on the roughness of the seafloor, the swath width on a flat bottom is generally maximum six times the water depth. For further information on the system, consult https://www.km.kongsberg.com/. Responsible person during this cruise / PI: Luis Batista. Description of data processing: Postprocessing and products were conducted by the Seafloor-Imaging & Mapping group of MARUM/FB5, responsible person Paul Wintersteller (seafloor-imaging@marum.de). The open source software MB-System (Caress, D. W., and D. N. Chayes, MB-System: Mapping the Seafloor, https://www.mbari.org/products/research-software/mb-system, 2017) was utilized for this purpose. . SVPs taken during this cruise were not sufficient enough to correct the recorded bathymetric data. Therefor sound velocity profiles were modelled using reference profiles from the world ocean atlas (S. Levitus, 1982), extracted and calculated through the MB-System program mblevitus by utilizing the DelGrosso equation. The surface sound speed has then been adapted according to the recordings during this cruise while there were no further corrections for roll, pitch and heave applied during postprocessing. A tide correction was applied, based on the Oregon State University (OSU) tidal prediction software (OTPS) that is retrievable through MB-System. CTD measurements during the cruise were sufficient to represent the changes in the sound velocity throughout the study area. Using Mbeditviz, artefacts were cleaned manually. NetCDF (GMT) grids of the edited data as well as statistics were created with mbgrid. The published bathymetric EM120 grid of the cruise M79/2 has a resolution of 35 m. No total propagated uncertainty (TPU) has been calculated to gather vertical or horizontal accuracy. A higher resolution is, at least partly, achievable. The grid extended with _num represents a raster dataset with the statistical number of beams/depths taken into account to create the depth of the cell. The extended _sd -grid contains the standard deviation for each cell. The DTMs projections are given in Geographic coordinate system Lat/Lon; Geodetic Datum: WGS84. All grids produced are retrievable through the PANGAEA database (www.pangaea.de). Chief Scientist: Christian Hübscher christian.huebscher@uni-hamburg.de CR: https://www.tib.eu/de/suchen/id/awi%3Adoi~10.2312%252Fcr_m79_2/ CSR: https://epic.awi.de/id/eprint/37063/31/m79-expeditionsheft.pdf

Description: Bathymetry data was acquired during R/V METEOR cruise M84/4 at the Galician Shelf off Northwest Spain in the Northeast Atlantic between 01.05.2011 and 28.05.2011. The main objectives of the cruise were the investigation of sediment transport processes from shallow to deep waters, understanding sediment dynamics, analysis of material downslope processes and the reconstruction of modern and past environmental conditions. The cruise comprised seismic, sedimentological, magnetic, geochemical and palaeoceanographic methods. Extensive bathymetric mapping during M84/4 based on the multibeam echosounders (MBES) KONGSBERG EM710 and EM122 provided the basis for sediment coring and additional investigations. Hydroacoustic data revealed the diverse morphology in the study area, driven by both sedimentary and tectonic processes, including contouritic deposits, slope gullies, canyon/channel systems, ridges and seamounts. The sub-bottom profiler PARASOUND, multichannel seismics, ADCP, several coring devices and the electromagnetic profiler MARUM-NERIDIS III complemented the research programme of the cruise. CI Citation: Paul Wintersteller (seafloor-imaging@marum.de) as responsible party for bathymetry raw data ingest and approval. Description of the data source: During the M84/4 cruise, the hull-mounted KONGSBERG EM710 multibeam echosounder (MBES) was utilized to perform bathymetric mapping of high resolution in water depths of 3 m to – theoretically – 2000 m. Best quality data is, however, achieved in water depths of less than 600 m, and in rough weather conditions less than 400 m. The EM710 operates at sonar frequencies of 70 to 100 kHz. Three to five sectors divide the transmit fan, where distinct frequencies or waveforms are transmitted sequentially. The swath width can reach 5.5 times the water depth. 256 beams with an acoustical 1°(TX)/1°(RX) footprint are formed for each ping. The transmit fan is electronically stabilized for roll, pitch and yaw. Combining phase and amplitude bottom detection algorithms allows achieving best possible accuracy. For further information, consult: https://epic.awi.de/id/eprint/26726/1/Kon2007b.pdf. The position and depth of the water column is estimated for each beam by using the detected two-way-travel time and the beam angle known for each beam, ray-traced through the water column, utilizing a proper sound speed profile. During the M84/4 cruise, the EM710 was running in a 24-hour watch mode, in addition to the EM122 and the PARASOUND sub-bottom profiling system. Acquisition of EM710 data was reliable during the whole cruise; however, problems occurred during rough weather conditions, since the EM710 lost the bottom signal in depths of more than 400 m. Responsible person during this cruise / PI: Tilmann Schwenk (tschwenk@marum.de). Description of data processing: Postprocessing and products were conducted by the Seafloor-Imaging & Mapping group of MARUM/FB5, responsible person Paul Wintersteller (seafloor-imaging@marum.de). The open source software MB-System (Caress, D. W., and D. N. Chayes, MB-System: Mapping the Seafloor, https://www.mbari.org/products/research-software/mb-system, 2017) was utilized for this purpose. Tide corrections and a sound velocity profile were applied to the M84/4 data; there were no corrections for roll, pitch and heave. A tide correction was applied, based on the Oregon State University (OSU) tidal prediction software (OTPS) that is retrievable through MB-System. CTD measurements during the cruise were sufficient to represent the changes in the sound velocity throughout the study area. Using Mbeditviz, artefacts were cleaned manually. NetCDF (GMT) grids of the edited data as well as statistics were created with mbgrid. The published bathymetric EM710 grid of the cruise M84/4 has a resolution of 35 m. No total propagated uncertainty (TPU) has been calculated to gather vertical or horizontal accuracy. A higher resolution is, at least partly, achievable. The grid extended with _num represents a raster dataset with the statistical number of beams/depths taken into account to create the depth of the cell. The extended _sd -grid contains the standard deviation for each cell. The DTMs projections are given in Geographic coordinate system Lat/Lon; Geodetic Datum: WGS84. All grids produced are retrievable through the PANGAEA database (www.pangaea.de). Chief Scientist: Till J. J. Hanebuth (thanebuth@coastal.edu) CR: https://www.tib.eu/de/suchen/id/awi%3Adoi~10.2312%252Fcr_m84_4/ CSR: https://www.ldf.uni-hamburg.de/meteor/wochenberichte/wochenberichte-meteor/m84/m84-4-scr.pdf