Dives to the Deep by AUV 'r2D4' in Five Years

摘要

After launching in 2003, the AUV(Autonomous Underwater Vehicle) "r2D4" carried out 6 series of dives to the deep. The first series of dives is survey of sea bottom along a fauk line off Sado island. Since it was the first sea trails, We selected a simple topography of the sea bottom to avoid dangerous situation. Three dives were successfully carried out resulting in getting clear side scan images of the fault, which is one of big advantages of introducing AUV for underwater survey. Then, we gradually improved its performance step by step by letting the AUV dive in more difficult environment and situation. In 2005, the vehicle descended through a 3-knot ocean current into the caldera of submarine volcano. In 2006, it went along a narrow rift valley of segment 16 of central Indian mid-ocean ridge system. In this paper, we summarize dives of r2D4 carried out so far and its potential for deep ocean survey.