Fig. 2From: Self-potential mapping using an autonomous underwater vehicle for the Sunrise deposit, Izu-Ogasawara arc, southern JapanApparatus used in the present study. a Photograph of the side-view of the AUV Jinbei (Hyakudome et al. 2012). b Configuration of the present survey with a 10-m-long FRP electrode rod. Open squares on the cable show locations of five Ag/AgCl electrodes. The solid square is that of a reference (common) Ag/AgCl electrode. Orange ellipsoids show the locations of small plastic buoys to keep the rod neutral. The data logger is mounted outside of the AUVBack to article page