ALBERT

Description: In this study ship- and AUV-based multibeam data from the German Mn-nodule license area in the Clarion-Clipperton Zone (CCZ; eastern Pacific) are linked to ground truth data from optical imaging. Photographs obtained by an AUV enable semi-quantitative assessments of nodule coverage at a spatial resolution in the range of meters. Together with high resolution AUV bathymetry this revealed a correlation of small-scale terrain variations (〈 5 m horizontally, 〈 1 m vertically) with nodule abundance. In the presented data set, increased nodule coverage could be correlated with slopes 〉 1.8° and concave terrain. On a more regional scale, factors such as the geological setting (existence of horst and graben structures, sediment thickness, outcropping basement) and influence of bottom currents seem to play an essential role for the spatial variation of nodule abundance and the related hard substrate habitat. AUV imagery was also successfully employed to map the distribution of re-settled sediment following a disturbance and sediment cloud generation during a sampling deployment of an Epibenthic Sledge. Data from before and after the "disturbance" allows a direct assessment of the impact. Automated image processing analyzed the nodule coverage at the seafloor, revealing nodule blanketing by resettling of suspended sediment within 16 hours after the disturbance. The visually detectable impact was spatially limited to a maximum of 100m distance from the disturbance track, downstream of the bottom water current. A correlation with high resolution AUV bathymetry reveals that the blanketing pattern varies in extent by tens of meters, strictly following the bathymetry, even in areas of only slightly undulating seafloor (〈 1 m vertical change). These results highlight the importance of detailed terrain knowledge when engaging in resource assessment studies for nodule abundance estimates and defining minable areas. At the same time, it shows the importance of high resolution mapping for detailed benthic habitat studies that show a heterogeneity at scales of 10 m to 100 m. Terrain knowledge is also needed to determine the scale of the impact by seafloor sediment blanketing during mining-operations.

Description: Die Erfindung betrifft eine Tiefsee- LED-Leuchte-Vergussverfahren mit den Schritten: Konfigu- ration einer LED-Leuchte mit mindestens einer LED mit je- weiliger elektrisch kontaktierender Zuleitung; Einbringung der konfigurierten LED-Leuchte in eine Vergussform und Fixierung zumindest einer Zuleitung an der Vergussform, wobei zu vergießende Bauteile der LED-Leuchte die Wan- dungen der Vergussform nicht berühren; Verschwenken der Vergussform relativ zur Umgebung in einem Schwerkraft- system; Einbringen einer Vergussmasse in die Verguss- form bis die zu vergießenden Bauteile der LED-Leuchte voll- ständig mit der Vergussmasse umschlossen sind; optische Qualitätskontrolle auf Blasenfreiheit der Vergussmasse wäh- rend des Aushärtens und bedarfsweise wiederholendes Ver- schwenken der Vergussform, so dass innerhalb der Ver- gussmasse befindliche Blasen bzw. Gaseinschlüsse aus der Vergussmasse herausgefördert sind. Ferner betrifft die Erfindung eine LED-Leuchte mit mindes- tens einer LED, mindestens einer die LED elektrisch kon- taktierenden und mit Energie versorgenden Zuleitung, wobei die LED in einer Vergussmasse angeordnet ist, wobei die mindestens eine LED sowie optionale Bauteile der Tiefsee- LED-Leuchte und/oder gemeinsame oder jeweilige Träger und/oder Schnittstellen und/oder elektronische Bauteile voll- ständig von der Vergussmasse umschlossen sind.

Description: At a diameter of 200 m, the 1100 m deep Niua South hydrothermal field (NE Lau Basin) was studied in an interdisciplinary approach during the SOI funded Virtual Vents cruise in March of 2016. On the grounds of a previously generated 50 cm resolution AUV multi beam map, the projects backbone is formed by a fully color textured, 5 cm resolution photogrammetrical 3D model. Several hundred smaller and about 15 chimneys larger than 3 m were surveyed including their basal mounds and surrounding environment interconnecting to each other. This model was populated through exhaustive geological, biological and fluid sampling as well as continuous Eh measurements, forming the basis for highly detailed geological structural and biological studies resulting in 3D maps of the entire field. At a reasonable effort, such surveys form the basis for repetitive time series analysis and have the potential of a new standard in seafloor monitoring.

Description: Volcanism in the ocean basins is traditionally assumed to occur only at the plate margins (mid-ocean ridges, subduction zones, possibly also transform boundaries) and areas of intraplate hotspot activity related to thermal plumes in the mantle. As a result, abyssal areas away from hotspots are seldom explored systematically for signs of volcanism and are generally regarded as volcanically "dead". Here we present serendipitous results from the Peru Basin, a site of Mn-nodule accumulation which was targetted in 1989 for a large-scale disturbance experiment (the DISCOL experiment) to simulate the effects of seabed nodule mining. The area is truly intraplate - it is 700 km from the south American subduction zone or the Galapagos Islands and 2000 km from the East Pacific Rise. A return trip to DISCOL in 2015 to assess the extent of environmental recovery also included a remotely-operated underwater vehicle (ROV) dive on a small (300m high) seamount adjacent to the Mn-nodule field. ROV video records show the seamount is generally heavily sedimented but has a small (100x150m) pillow mound and an area of indurated calcareous sediments apparently cut by basaltic dykes near its summit. The summit is also cut by N-S and E-W-trending faults, some with up to 20m of throw, whose scarps expose thick sedimentary sequences. The virtual absence of sediment covering the pillows or dyke outcrops suggest that they are very recent - the thick sediment pile exposed on the fault scarps suggests that they were erupted on top of an old seamount. Regionally, acoustic data (bathymetry and backscatter from the ship-mounted multibeam system) shows several other seamounts in the region which may have experienced recent volcanic activity, although no sign of a linear volcanic chain is seen. Taken together, these observations suggest that, even at age 20Ma, the Nazca Plate is volcanically active.

Description: Mildly explosive volcanic eruptions on the deep seafloor have been demonstrated in several cases. In contrast, we present here evidence for highly explosive activity producing diatreme-like ejecta on the surrounding seafloor at the Charles Darwin Volcanic Field (CDVF) located at about 3600 m water depth on the lower southwestern slope of the Cape Verdean Island of Santo Antão. We examined the 1 km diameter Kolá volcanic crater using photogrammetric reconstructions derived from ROV-based imaging followed by 3D quantification using a novel remote sensing workflow. The measured and calculated parameters of physical volcanology derived from the 3D model allow us to get a handle on explosive volcanic processes on the deep seafloor. Kolá crater comprises a complicated lithologic succession of highly fragmented deposits, including spheroidal juvenile lapilli that may contain quenched carbonatite melts, and were likely formed by spray granulation. The deposits comprise numerous well-rounded clasts of MORB-type gabbroic country rocks with diameters up to 20 cm, probably entrained and abraded by fluidization within the vent, that were laterally transported for hundreds of meters through water. In spite of the great depth, the Kolá crater features dense but highly fragmented volcanic deposits with an unexpected combination of large clast sizes and wide clast dispersal. This suggests an energetic eruptive environment which may have similarities with that seen in maar-type eruptions on land. The occurrence of carbonatite in the juvenile clasts provide evidence for a CO2-rich magmatic fluid involved in the explosive events.

Description: The power of quantitative visual observations has yet to be brought to bear on most aspects of seafloor volcanic studies. Yet changes in volume, appearance and colonisation of magmatic and hydrothermal constructs (vents, flows, chimneys, microbial mats etc.) are direct consequences of changes in the magmatic system and can provide quantitative estimates of heat and material transport not available through more localized observation or sampling. Photogrammetric techniques applied to dedicated ROV imagery allow the reconstruction of a centimeter-scale, fully three dimensional model of seafloor features. On E/V Nautilus Leg 069/2 during the summer of 2015, this method was applied to major vents of the Mothra, Main Endeavour and High Rise sites at the Endeavour Segment, Juan de Fuca Ridge. Together with previous surveys at Mothra a) in 1997 (Yoerger et al., 2000) and b) in 2014 (see graphical abstract) as well as imagery collected during the annual Ocean Networks Canada servicing dives at all sites, we are able to construct a time series of vent development including sulfide buildup, erosion and changes in the habitat. For the first time, this can be done on the grounds of a fully georeferenced, quantitative model.

Description: Sediment gravity cores recovered during the RV METEOR cruise M80/3 in 2010 around the northwestern end of the Cape Verde Archipelago contain three widespread hyaloclastic tephra layers. One of these layers occurs in two sediment cores 40 km apart. The blocky shapes of the vesicle-poor/-free glass-shards clearly indicate their origin from a subaqueous eruption. There are three potential sources in the northwestern Cape Verdean Seamount Province: (1) the Nola Seamount, (2) the Sodade Seamount and (3) the Charles Darwin Volcanic Field. Using geochemical fingerprinting the hyaloclastic glass-shards could be unambiguously correlated to the Charles Darwin Volcanic Field. This is a deep-sea volcanic field consisting of at least 14 eruption centers all at 〉2,850 m below sea level, located about 100 km east of the core locations. Previous studies have documented widespread tephra distributions from relatively shallow (〈 500 mbsl) submarine explosive eruptions, but here we record such a widespread tephra from a deep-sea (probably 〉3000 mbsl) eruption. We discuss the mechanisms of formation and far transport of the hyaloclastic particles.

Description: Planetariums are not just for education, or even astronomy: they could display all sorts of data, if only scientists thought to use them, says Tom Kwasnitschka.

Description: In this opinion paper, we, a group of scientists from environmental-, geo-, ocean- and information science, argue visual data exploration should become a common analytics approach in Earth system science due to its potential for analysis and interpretation of large and complex spatio-temporal data. We discuss the challenges that appear such as synthesis of heterogeneous data from various sources, reducing the amount of information and facilitating multidisciplinary, collaborative research. We argue that to fully exploit the potential of visual data exploration, several bottlenecks and challenges have to be addressed: providing an efficient data management and an integrated modular workflow, developing and applying suitable visual exploration concepts and methods with the help of effective and tailored tools as well as generating and raising the awareness of visual data exploration and education. We are convinced visual data exploration is worth the effort since it significantly facilitates insight into environmental data and derivation of knowledge from it.