A novel method for hydrothermal vents prospecting using an autonomous underwater robot

In this paper we address the problem of localizing active hydrothermal vents on the seafloor using an autonomous underwater vehicle (AUV). Woods Hole Oceanographic Institution's Autonomous Benthic Explorer (ABE) (see Fig.1) AUV has been successfully used in several hydrothermal vents prospecting missions. Recently, a three-stage nested approach [1] has been introduced. It consists in surveys at different altitudes to finally photograph the venting structures flying very close to the seafloor. In this paper, we introduce a new strategy for ABE's movement in surveys at higher altitude (phase-1): ABE moves along predesigned tracklines sampling the seawater; when some conditions on collected data are encountered, it starts a spiral movement to fly over areas likely to contain active vent fields. Results of the proposed algorithm tested on data coming from previous ABE's missions are shown and assess the efficiency and reliability of the method.