"Reconnaissance aircraft" explores deep sea

Autonomous underwater vehicle independently collects data in the oceans

An autonomous underwater vehicle (AUV) of the French research institute IFREMER in action. Note: Since the exact appearance of the device is not yet known, as the model is only set in the context of a European tender. Therefore, the picture is only an example of typical devices of this class. © IFREMER
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Using the so-called "Autonomous Underwater Vehicle (AUV)" physical and chemical conditions in the water column and on the seabed can be recorded. Unlike a "Remote Operated Vehicle (ROV)", the AUV is not connected to the ship by a cable, but dives autonomously in the water column. The Leibniz Institute for Marine Sciences (IFM-GEOMAR) in Kiel, with the help of the German Research Foundation (DFG), is also creating such a system which, together with the ROV6000, will soon explore the deep sea.

At the beginning of an AUV mission, the vehicle's destination, course and task are programmed. The torpedo-like systems can handle several issues during a mission. For this purpose, different measuring systems are installed on the AUV. The currently provided facilities for measuring seawater parameters are a temperature and pressure probe (CTD) and a particle sensor. In addition, a high-resolution sonar, a side-scan sonar, a sonar, the depth profiles of the sediment created, and a photo camera for mapping and documentation of the seabed are used.

Perfect underwater team

But in addition to the AUV, IFM-GEOMAR will also have the world's most modern ROV in the future. Professor Peter Herzig, Director of the Leibniz Institute for Marine Sciences, compares the special areas of application of the two diving robots: "In research, we use the AUV in a similar way to a reconnaissance aircraft. This device glides about 200 meters above the seabed and provides us very fast data from a relatively large area. In combination with the ROV Kiel 6000, which collects detailed information close to the ground, we have tools that complement each other perfectly. "

"In October 2008 there will be a first joint project of ROV and AUV, " said Colin Devey, Klas Lackschewitz and Thomas Kuhn from IFM-GEOMAR. The aim is to measure and sample the water column and the seabed at the Mid-Atlantic Ridge between 4 ° and 11 ° S in water depths up to 4, 000 meters. There occur up to 400 ° C hot solutions from the seabed.

The exploration of hot springs on the seabed

In order to be able to realistically assess the significance of such hot springs in the global temperature and material budget, nationwide measurements are required there. For this purpose, the AUV will first measure the properties such as temperature and salinity of the water column over the hot springs and high-resolution (<1 meter) mapping the seabed relief in the vicinity of the sources. On the basis of these results, the ROV will then be used specifically in the area of ​​the hydrothermal wells to take samples and perform experiments on the seafloor. display

With the joint use of ROV and AUV, we not only effectively exploit the expensive shipping time, but also address new scientific issues that require the simultaneous study of parameters in the water column and the seafloor Lack, explains Lackschewitz. This may be the case, for example, with submarine volcanic eruptions or submarine landslides triggered by seabake. "All in all, we hope that this will increase the understanding of the sea system and its role for humans as a source of raw materials and food, as a climate factor, but also as a source of rest and relaxation" Dev, Devey summarizes the high expectations.

(GeoUnion, 20.07.2007 - AHE)