DeepSurveyCam — A Deep Ocean Optical Mapping System

Underwater photogrammetry and in particular systematic visual surveys of the deep sea are by far less developed than similar techniques on land or in space. The main challenges are the rough conditions with extremely high pressure, the accessibility of target areas (container and ship deployment of robust sensors, then diving for hours to the ocean floor), and the limitations of localization technologies (no GPS). The absence of natural light complicates energy budget considerations for deep diving flash-equipped drones. Refraction effects influence geometric image formation considerations with respect to field of view and focus, while attenuation and scattering degrade the radiometric image quality and limit the effective visibility. As an improvement on the stated issues, we present an AUV-based optical system intended for autonomous visual mapping of large areas of the seafloor (square kilometers) in up to 6000 m water depth. We compare it to existing systems and discuss tradeoffs such as resolution vs. mapped area and show results from a recent deployment with 90,000 mapped square meters of deep ocean floor

Caracterización de grandes estructuras sismogénicas y tsunamogénicas del Golfo de Cádiz con tecnologías de muy alta resolución : Cruise Report INSIGHT-Leg 1

Cruise Report INSIGHT-Leg 1 R/V Sarmiento de Gamboa (SDG-68) 29th April - 18th May 2018.-- 139 pages, figures, tables, 2 annexesLarge earthquakes, submarine landslides and the tsunami they might originate are geohazards of great societal concern because they may impact world economies and struck coastal populations. Examples of these events are the 2004 northern Sumatra and 2011 Tohoku earthquakes and respective tsunamis. However, earthquakes of magnitude Mw > 8.0 in areas of relatively slow tectonic deformation and with long recurrence intervals, such as the external part of the Gulf of Cadiz, might also have a significant impact. The most relevant is the 1755 Lisbon earthquake, related submarine landslides and destructive tsunami. The occurrence of faults and landslides able to trigger a catastrophic tsunami reveals that the Gulf of Cadiz is one of the highest geohazard areas in Europe. Migration of sub-seafloor fluids has also been widely documented in the Gulf of Cadiz and such fluids are strongly related to the earthquake cycle and to the occurrence of submarine landslides. Understanding of these active processes can only be developed by using ultra-high-resolution tools able to map with unprecedented detail faults, submarine landslides and fluid escape structures. State-of-the-art techniques are used during INSIGHT-Leg 1, such as microbathymetry obtained from an autonomous underwater vehicle (AUV), sub-bottom profiles, HR multi-channel seismic data (MCS), and groundtruthing using sediment coresWe gratefully acknowledge financial support from Ministerio Economia y Competividad through national project INSIGHT “ImagiNg large SeismogenIc and tsunamiGenic structures of the Gulf of Cadiz with ultra-High resolution Technologies (INSIGHT-Leg1)” (CGL2011-30005-C02-02, PIs: Roger Urgeles and Eulàlia Gràcia) and Ocean Facilities Exchange Group (OFEG) for allowing us to use the AUVs “Abyss” from GEOMAR (Germany

Detailed Mapping and Sampling of the Reykjanes Ridge, Cruise No. MSM75, 29 June 2018 - 8 August 2018, Reykjavik - Reykjavik, REYKJANES

Hotspot-influenced spreading axes are characterized by a shallow axis, thickened crust, and possibly by higher-than-normal eruption frequency, all signs of an excess of magma and heat being supplied to such ridges by the hotspot. Despite this, these ridges are also characterized by an apparently lower-than-average incidence of high-temperature hydrothermal venting, raising questions about their thermal budget. The type example for hotspot-ridge interaction is the Reykjanes Ridge south of Iceland, which shows abnormally shallow bathymetry between the Reykjanes Peninsula at ca. 63°N and the Charlie Gibbs Fracture Zone at 53°N.The seafloor surrounding the present spreading axis is also characterized by V-shaped bathymetric ridges, thoughtto be produced by regions of excess melting migrating along the axis through time. Cruise MSM75aimed to produce geological maps of four key areas along the ridge -one with thickened crust where a V-shaped ridge intersects the present-day axis, one with thickened crust but no on-axis V-shaped ridge anomaly, a third with more normal crustal thickness and an axial valley and a fourth at the only known, but up to present unsampled, Reykjanes hydrothermal site Steinaholl. This geological mapping is to be usedto investigate questions of variations in eruption size or frequency away from Iceland, the interplay between magmatism and tectonism, the axial volcanology of V-shaped ridges and how thick crust is cooled in the apparent paucity of high-temperature vent fields

Multibeam bathymetry processed data (Reson SeaBat T50-S working area dataset) of AUV ABYSS during cruise AL532, East Sicily continental margin

The data comprise two bathymetric grids acquired with a 200 kHz multibeam echosounder carried by the Autonomous Underwater Vehicle (AUV) ABYSS. The data was collected during research cruise AL532 with RV ALKOR in January 2020. Both grids are fully processed and each cover an area about 2.5 x 2.5 km of the seafloor with a grid spacing of 2m

Evaluierung der Gewässerschutzberatung in Hessen im Kontext der EU-Wasserrahmenrichtlinie: Auswirkungen auf Wissen und Handeln von Landwirten

Zusammenfassung Im Auftrag des Hessischen Ministeriums für Umwelt, Klimaschutz, Landwirtschaft und Verbraucherschutz untersuchte das Thünen-Institut für Ländliche Räume von 2012 bis 2015, welche Effekte die hessische WRRL-Gewässerschutzberatung, welche das Land im Rahmen der Umsetzung der Europäischen Wasserrahmenrichtlinie (WRRL) anbietet, auf den Wissenszuwachs, das Problembewusstsein und daraus resultierende Handlungsänderungen von Landwirten und Winzern in Hinsicht auf Stickstoff hat. Den Kern der Studie bildete eine standardisierte Befragung, die mit Antworten von 1.477 Landwirten (sowie 131 Winzern; Rücklauf jeweils 33 %) eine quantitative Analyse und statistische Testverfahren ermöglichte. Die Befragung wurde in der Vorbereitung vor allem durch Experteninterviews und im Anschluss durch 18 qualitative Vertiefungsinterviews mit Landwirten sowie Validierungsrunden mit Beratern und Landwirten ergänzt. Die Studie zeigt, dass die Gewässerschutzberatung trotz der zum Befragungszeitpunkt erst kurzen Laufzeit von ein bis zwei Jahren das Problembewusstsein von Landwirten sowie ihre Gewässerschutzkompetenz erhöhte und in wichtigen Details zu Handlungsänderungen führte. Größere Handlungsänderungen wie die Aufnahme des Zwischenfruchtanbaus konnten bisher offenbar kaum induziert werden. Doch mit Düngermenge, Umbruchzeitpunkt, Sortenwahl und Flächenanteil beeinflusst die Beratung wichtige Bewirtschaftungsdetails, die positiv für den Gewässerschutz sind. Zwar wurde auch deutlich, dass sich tendenziell eher besser ausgebildete und informierte Landwirte an der Beratung beteiligen. Doch offensichtlich hilft die Beratung auch diesen Betrieben, Gewässerschutz stärker in ihr Handeln zu integrieren. Bei kostenintensiven wichtigen Maßnahmen, wie dem Ausbau von Lagerkapazitäten für Gülle, ist die Beratung kein geeignetes politisches Instrument, kann aber das Verständnis für Maßnahmen erhöhen. Der Faktor Zeit konnte als entscheidend für die Beratungswirkung bestätigt werden und spricht auch für die Fortführung der Beratung.////////////////////////////////Summary From 2012 to 2015 the Thünen-Institute of Rural Studies evaluated the Hessian extension service, provided by the state in the context of the Water Framework Directive (WFD). The ealuatio osides the seies’ effets o faes’ ad iegoes’ koledge leels, poble aaeess ad aageet hages egadig itoge. The stud’s oe as a stadadized questionnaire survey with answers from 1477 farmers (wine-growers: 131; response rate each 33 %) which allowed for quantitative analyses and statistical testing. The survey was complemented by semi-structured expert interviews before the survey, and 18 in depth-interviews as well as one validation round with farmers and two with extension workers after the survey. The study shows that even though the extension service had been carried out for only one to two eas at the tie of the sue, faes’ pole aaeess and their competence levels for water protective management were raised and important details of management practices were improved. It seems that bigger management changes like the adoption of catch crops could hardly be induced, at least up to the time of the survey. However, the amount of added nutrients, the time-point for turning over the soil, choice of varieties of crops and share of land cultivated with catch crops were important management details which were influenced by the extension service. Even though farmers with higher levels of education and information were somewhat more likely to take part in the extension activities, there was some scope to improve their abilities to incorporate water protection practices in their management. While extension is not the best suited instrument to induce important cost intensive measures like increasing storage capacity for slurry, it can increase understanding for measures. Time was identified as a decisive factor for the extension services to take effect, and this suggests that the extension service is worth being continued

Merged and geo-referenced Side Scan Sonar map from AUV dives during SONNE cruise SO242/1

The AUV-acquired Side Scan Sonar (SSS) data during RV SONNE cruise SO242_1 of the entire DEA is provided as GeoTIFF here (0.5 x 0.5 m resolution, UTM 16S)

Merged and geo-referenced bathymetric raster from AUV MBES surveys during SONNE cruise SO242/1

This dataset is a bathymetric raster (GeoTIFF, UTM 16S) with a 2 x 2 m resolution merged from three different AUV MBES surveys (Abyss192 - SO242/1_047-1; Abyss193 - SO242/1_060-1; Abyss194 - SO242/1_069-1) conducted during cruise SO242_1 with the German RV SONNE. It includes the entire DEA in the center and extends towards a mountain area NE of the DEA. The provided raster is corrected for lateral and vertical offsets based on the ship-acquired MBES (Kongsberg EM122 mounted in RV SONNE) dataset (https://doi.pangaea.de/10.1594/PANGAEA.905579) as reference layer