Dives of cruising-AUV “JINBEI” to methane hydrate area on Joetsu knoll and Umitaka Spur

Autonomous Underwater Vehicle “JINBEI”, constructed in 2012, is a cruising type AUV with a weight of 2 ton and a length of 4.0m. The major purposes are observation of underwater CO2 distribution in deep sea and exploration of seabed mineral resources. It has four rear-thrusters, two mid-ship azimuthal thrusters, and a rear X-rudder. The AUV is equipped with three main sensors; a multi-beam echo sounder, a side scan sonar, and a hybrid CO2-pH sensor. During KY12-10 cruise in August 2012, we deployed “JINBEI” at a methane hydrate area in Joetsu knoll and Umitaka Spur, Japan Sea. The depth of the area is 850-950m. The vehicle cruised over the methane hydrate area at a speed of 2 knots. We obtained high-resolution side scan images of hydrate mounts as well as methane plumes. At same time, the CO2-pH sensor detected the methane plumes indirectly. Through the dives, we confirmed that the cruising AUV “JINBEI” is one of powerful tool for survey of scientific observations.