Use of ROVs and AUVs for observations, measurements and experiments in the deep-sea

Unmanned underwater vehicles made their way into today’s deep-sea research as well. Selected scientific ROV and AUV deployments at a deep-sea observatory and at submarine methane seeps are presented. High quality field observations are the basis of the comprehension of interactions between biology, physics and geochemistry and the understanding of process in marine sciences, respectively. Complex underwater platforms such as remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) are commonly deployed today in marine research. Under the lead of the AWI several expeditions have been conducted to Håkon Mosby Mud Volcano (HMMV, western Barents Sea) where methane is released at the seafloor in gaseous as well as in dissolved form. Using Ifremer’s ROV Victor 6000 the micro-topography of HMMV was mapped by high resolution multibeam echo sounders [1]. After a visual exploration of the different habitat types by the ROV [2] a systematic video mosaic was recorded with Victor 6000’s downward-looking camera. The geo-referenced video mosaics were interpolated to a habitat map (Figure 1). Although the results were excellent, both, the hydro-acoustic as well as the video mapping could have been accomplished much faster using an AUV instead of a ROV (however, there was no operational AUV available at that time). However, as later efforts to use an AUV at this location to survey the dynamics of a methane plume discharged from HMMV showed impressively, ROV deployments might be more time consuming but may be at the same time more reliable in rough weather areas. For numerous other investigations with manipulation tasks and targeted sampling such as the quantification of bubble ebullition rates by image analysis and the determination fluid flow by an acoustic travel time current meter as well as for the deployment of an autonomous micro profiler module the full size ROV Victor 6000 was very well suited [2, 3]. At the deep-sea long term observatory HAUSGARTEN [4] different kinds of experiments were performed by means of the ROV in order to learn more about the survival strategies of benthic deep-sea organisms (saving energy by waiting for eventual food supply versus actively moving for seeking food): for this purpose e.g. fish bites were deployed and algae were distributed on the seafloor, respectively, and after a representative exposure time sampled by push cores for further analysis. Colonization experiments with plates from different materials were conducted at HAUSGARTEN and inspected one year later by the ROV. In order to understand the effect of near bottom flow current meter measurements were performed by the ROV around hydrodynamic obstacles like rocks. Furthermore a flume was installed at 2500 m depth in the main current direction and visited for intensive sampling and measurements two years later by Victor 6000. As a conclusion one can state that for a large variety of manipulation tasks in deep-sea research full size ROVs are indispensable tools. AUVs can in principle be deployed for touchless hydro-acoustic, visual and sensor surveys of larger areas. However, there is still room for improvement in respect to situation-specific mission changes. The development of hybride ROVs as well as advances in sensor systems, mission planning and autonomy will further increase the flexibility of underwater robots. References [1] Jerosch, K., Schlüter, M., Foucher, J.-P., Allais, A.-G., Klages, M. and Edy, C.: Spatial distribution of mud flows, chemoautotrophic communities, and biogeochemical habitats at Håkon Mosby Mud Volcano, Marine Geology 243, 1–17, 2007. [2] Niemann, H., Lösekann, T., de Beer, D., Elvert, M., Nadalig, T., Knittel, K., Amann, R., Sauter, E., Schlüter, M., Klages, M., Foucher, J.-P. and Boetius, A.: Novel microbial communities of the Haakon Mosby mud volcano and their role as a methane sink, Nature, 443, 854-858, 2006. [3] Sauter, E., Muyakshin, S.I., Charlou, J.L., Schlüter, M., Boetius, A., Jerosch, K., Damm, E., Foucher, J.P. and Klages, M.: Methane discharge from a deep-sea submarine mud volcano into the upper water column by gas hydrate-coated methane bubbles, Earth and Planetary Science Letters, 243(3), 354-365, 2006. [4] Soltwedel, T., Bauerfeind, E., Bergmann, M., Budaeva, N., Hoste, E., Jaeckisch, N., Juterzenka, K. v., Matthießen, J., Mokievsky, V., Nöthig, E.M., Quéric, N., Sablotny, B., Sauter, E., Schewe, I., Urban-Malinga, B., Wegner, J., Wlodarska-Kowalczuk, M. and Klages, M.: HAUSGARTEN: multidisciplinary investigations at a deep-sea, long-term observatory in the Arctic Ocean, Oceanography, 18(3), 46-61, 2005

Untermeerischer Grundwasseraustritt : das EU-Projekt Sub-GATE

Submarine groundwater discharge (SGD) is known from many coastal areas around the globe. Although recognised to be an important transport pathway for pollutants and nutrients from groundwater aquifers into coastal waters quantifying SGD is still difficult. Recent studies suggest SGD to contribute much more to total fresh water runoff and in particular to the exchange of solutes than previously assumed. A multidisciplinary approach was chosen for the EU project "Sub-GATE" for investigating different phenomena associated with SGD in the main target area Eckernförde Bay (Western Baltic): Beside a qualitative, process-oriented understanding obtained by geological, biological, and geochemical field work discharge rates are to be quantified by isotope methodes as well as by a groundwater supply model over the catchment area and diagenetic modelling

From Basic Research to Application - Technology Transfer from AWI

For a responsible development of the Arctic, new remote sensing technologies and services are of great importance. Many of such innovations are based on scientific research. However, it is not trivial that they find their way into application. In order to ease this kind of transfer across the interface between academia and industry, the Alfred Wegener Institute has established a technology transfer office (TTO). The TTO takes up inventions and business ideas emerging from scientific research and supports innovators and entrepreneurs to progress them into the respective markets. The other way round, the TTO serves as the contact point for stakeholders from industry, governmental and non-governmental bodies to forward specific problems into the scientific community. Here we present two examples to illustrate the AWI technology transfer approach: 1) Planned for 2022, the German hyperspectral earth observation satellite EnMAP (Environmental Mapping and Analysis Programme) will measure the reflected radiance from the earth’s surface over a wide hyperspectral wavelength range (from visible to short wave infrared). In order to provide correct hyperspectral satellite products such as land cover (natural surfaces, urban), surface waters, surface mineralogy, hydrology (snow, moisture) etc. in a correct manner, it is necessary to normalize for the incidence and the reflection of light depending on the zenith and azimuth viewing geometries. This is performed by providing the bidirectional reflectance distribution function BRDF for different materials. Determination of BRDFs for terrestrial surfaces is very challenging especially for high latitudes due to the low solar altitude. For Arctic vegetation mapping, a specific satellite field goniometer was developed at AWI to perform such ground truthing (Buchhorn et al., 2013). The goniometer allows for mobile ground-based measurements in order to determine the BRDF for different vegetation types. It consists of an azimuth angle adjustment module mounted on a tripod with a zenith arc with sensor sled equipped with two portable spectro-radiometers, a GPS receiver, an NC-Eye camera system and a white reference panel. The goniometer was prototyped, patented and licensed to a precision mechanics manufacturer. The commercial system in this case addresses the scientific community and specialized service providers. 2) Starting with geophysical ice thickness measurements on sea-ice and using air-borne electromagnetic measuring systems (Krumpen et al. 2011) a group of AWI scientists developed specific sea-ice related services for scientific, governmental and private sector customers operating in Arctic sea-ice. Subsequently the AWI spin-off Drift & Noise Polar Services was established in 2014. The new business was developed towards near real-time remote sensing ice information products and sea-ice consultancy for safer and faster navigation through ice-covered waters. Ice charts and weather information are generated from SAR and optical imagery (e.g. Sentinel 1 and 2). Since reliable broadband data transfer channels do not exist, particularly for high latitudes, the start-up also develops appropriate data compaction and transfer protocols combined with hand-held mobile systems for nautical officers which allow for near real-time access to latest ice data onboard ship. Thus shipping companies are able to save time and fuel by adapting their route while increasing safety. Fig. 1: Portable field spectro-goniometer for EnMAP ground truthing (a). Hand-held sea-ice information system “Ice Pad” using merged optical and SAR imagery (b). References 1. M. Buchhorn, R. Petereit & B. Heim (2013) A Manual Transportable Instrument Platform for Ground-Based Spectro-Directional Observations (ManTIS) and the Resultant Hyperspectral Field Goniometer System. Sensors, 13 (12), 16105-16128, doi:10.3390/s131216105. 2. T. Krumpen, L. Rabenstein, & J. Hoelemann (2011) Quantifying Sea Ice Formation Rates in the Laptev Sea by Means of ENVISAT SAR Scenes and Airborne Ice Thickness Measurements. International Union of Geodesy and Geophysics (IUGG) General Assembly, Melbourne, Australia, 29 June 2011 - 7 July 2011, hdl:10013/epic.38551

Spatial distribution and budget for submarine groundwater discharge in Eckernförde Bay (Western Baltic Sea)

Submarine groundwater discharge (SGD) from subseafloor aquifers, through muddy sediments, was studied in Eckernförde Bay (western Baltic Sea). The fluid discharge was clearly traced by 222Rn enrichment in the water column and by the chloride profiles in pore water. At several sites, a considerable decrease in chloride, to levels less than 10% of bottom-water concentrations, was observed within the upper few centimeters of sediment. Studies at 196 sites revealed that >22% of the seafloor of the bay area was affected by freshwater admixture and active fluid venting. A maximal discharge rate of .9 L m−2 d−1 was computed by modeling pore water profiles. Based on pore water data, the freshwater flow from subseafloor aquifers to Eckernförde Bay was estimated to range from 4 x 106 to 57 × 106 m3 yr−1. Therefore, 0.3–4.1% of the water volume of the bay is replaced each year. Owing to negligible surface runoff by rivers, SGD is a significant pathway within the hydrological cycle of this coastal zone. High-resolution bathymetric data and side-scan sonar surveys of pockmarks, depressions up to 300 m long, were obtained by using an autonomous underwater vehicle. Steep edges, with depths increasing by more than 2 m within 8–10 m in lateral directions, equivalent to slopes with an angle of as much as 11°, were observed. The formation of pockmarks within muddy sediments is suggested to be caused by the interaction between sediment fluidization and bottom currents. Fluid discharge from glacial coastal sediments covered by mud deposits is probably a widespread, but easily overlooked, pathway affecting the cycle of methane and dissolved constituents to coastal waters of the Baltic Sea

World Marrow Donor Association guidelines for the reporting of novel HLA alleles

The guidelines for the implementation and reporting of HLA nomenclature for the World Marrow Donor Association have served as a reliable standard for communication of HLA data in the hematopoietic cell transplantation process. Wider use of next-generation sequencing made a special provision of the guidelines increasingly pertinent: how to communicate novel HLA alleles. Novel alleles need to be recognized by the WHO Nomenclature Committee for Factors of the HLA system to obtain official allele designations. Until then they have to be handled according to the specific rules. Leaving the actual rules basically unchanged we give some advice on how to communicate novel alleles to best facilitate the search process for cases where novel alleles are identified on donor or patient side.Scopu

Mating plugs in polyandrous giants: Which sex produces them, when, how and why?

10.1371/journal.pone.0040939PLoS ONE77