10:45 AM - 11:00 AM
[SCG61-19] A new coring systm for ROV
The coring system has been developed by Koken Boring Machine Co. Ltd. The drilling rod consists of a rotating outer pipe and a non-rotating inner pipe, which enables to take relatively soft rocks. The inner pipe is a little inclined in the upper part, and hence cores are snapped off at this inclined part when drilling reaches there. A straight line indicating orientation can be marked to a core by a tip installed inside of the inner pipe. Drilling water circulation is inverse (suction) to that of common boring systems, which makes coring operation and a target rock clearly visible from an ROV without discharge of drilling slime. Drilled cores are suck to a core rack by the inverse water flow. Ten cores can be separately stored in the core rack, and a core storage compartment can be changed by moving a lever with a manipulator.
The coring system was tested during the R/V Shinsei-maru KS-17-4 cruise in May 2017 using the ROV HyperDolphin of JAMSTEC. Three dives were conducted at the Toshima Hole in the northern part of the Izu-Ogasawara (Bonin) Arc, and cores of volcanic rocks with orientation marks were successfully retrieved. We plan to further improve the coring system by accumulating experience on various target rocks and operation conditions.