Observation of deep seafloor by autonomous underwater vehicle

Abstract

The AUV (Autonomous Underwater Vehicle) is a dynamically stable platform for visual and acoustic observation of the deep sea floor. It can automatically take images of seafloor in high resolution. Two examples of observation carried out by the AUVs r2D4 and Tuna-Sand show significant advantage of the AUV and give us various ideas of AUV application. The first example is the dive to Kuroshima Koll by the hovering type AUV Tuna-Sand in June 2010 following the results of survey by the cruising type AUV r2D4 in January 2010. AUV Tuna-sand brought us photo images of the seafloor where unusual features in the side scanning sonar image captured by the AUV r2D4 were found. Second example is twelve dives over the gas-hydrate field in Toyama bay and took about 7,000 pictures from 2.2 meters above the floor in 1,000 meter depth. One of the mosaic shows that there are 3,500 snow crabs (Chionoecetes japonicas) in a 40 meters by 20 meters area.