An "Autonomous Underwater Vehicle (AUV)" for sPP 1144 and German marine science

• Antragsteller: Professor Dr. Colin Devey
• Fachliche Zuordnung: Paläontologie
• Förderung: Förderung von 2007 bis 2009
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 25986938

The aim of the Priority Program 1144 (Schwerpunktprogramm or "SPP" 1144) with the title "From mantle to ocean: Energy-, material-, and life-cycles at spreading axes" is to carry out a multi-disciplinary, multi-segment scale study of the mid-ocean spreading system in the Atlantic (see www.deridge.de). Much of the work on such systems needs to be carried out at the interface between the newly-created oceanic crust and the overlying water masses (effectively the lithosphere/hydrosphere boundary). It is at this interface that many of the biological, tectonic and mineralogical features which make the spreading axis systems so unique and important are concentrated. The processes occurring here happen at small scales, produce localised effects and vary rapidly – the interface is highly dynamic. Studying this dynamic interface from a surface ship has several major disadvantages: - The low resolution of ship-mounted geophysical systems (swath sonar, seismics, magnetics etc.) due to their large distance from the object being studied. - The long transit times for equipment lowered for oceanographic, chemical or biological purposes on cables from a surface vessel (e.g. CTD). This makes imaging, sampling and analysing (Eh, CH4, H2 etc) both cumbersome and timeconsuming, severe drawbacks in a highly dynamic system. - The poor manoeuvrability, slow turning speed and lack of bottom-following ability of deep-towed operations aimed at bringing sensors closer to the seafloor. This makes deep-towed deployments in many ridge axes ineffective and/or hazardous to the equipment. To address these significant problems, a system is needed which is capable of being present for significant amounts of time close to the seafloor, is capable of acquiring most types of geophysical seafloor data (bathymetry, magnetics, gravity etc.) repeatedly on a raster and also has the ability to map gradients (compositional, physical, chemical) in the water column. This can be achieved by one of three options - an occupied submersible, a remotely-operated vehicle (ROV) or an autonomous vehicle (AUV). The logistics and costs involved in occupied submersibles are formidable. The use of a ROV, whilst the method of choice for precise, well controlled sampling, is a less than optimal use of resources for raster-type traverses - it ties up a ship, pilot, navigator etc. to follow a course which an autopilot could also navigate. The umbilical tether of an ROV can also present a major vehicle safety hazard in rough and hydrothermally-active terrains. It is for such automated, grid-like (but also gradient-following) work and for work in which tether-snagging is a concern that an AUV is uniquely suitable. We propose here to acquire, initially for use on cruises within the Schwerpunktprogramm 1144 and for other hydrothermal, spreading-axis studies, but long-term and in parallel to this for use by the entire German marine science community, an AUV. The AUV proposed here is the basic configuration consisting of vehicle, swath bathymetric, sidescan and sediment-penetrating sonars, optical backscatter sensor, navigation units, communications equipment and the facilities to transport, deploy, service and maintain the vehicle when at sea. It is assumed that users will acquire or adapt specialised sensors for this basic package to suit their particular needs, in part through funds from SPP1144. The AUV will be supported the new Technik- und Logistikzentrum at the Leibniz-lnstitut für Meereswissenschaften in Kiel. The Leibniz-Institut has committed both space and personell to maintain this vehicle in an operational status.

• DFG-Verfahren: Schwerpunktprogramme
• Teilprojekt zu: SPP 1144: Vom Mantel zum Ozean: Energie-, Stoff- und Lebenszyklen an Spreizungsachsen
• Großgeräte: Autonomes Unterwasserfahrzeug
• Gerätegruppe: 0480 Spezielle Fahrzeuge und Geräteträger der Meeresforschung (außer Schiffe 240)
• Beteiligte Personen: Dr. Klas S. Lackschewitz; Dr. Sven Petersen