Discovery of new submarine hydrothermal activity area off the western coast of Kumejima Island, Okinawa Prefecture
Researchers from National Institute of Advanced Industrial Science and Technology (AIST) conducted surveys of the seafloor off the coast around Kumejima Island, Okinawa Prefecture and Okinoerabujima Island, Kagoshima Prefecture using the research vessel Kaiyo Maru No.7 (499 tons; owned by Nippon Kaiyo Co., Ltd.) from August 20 to September 13, 2012 and discovered a new submarine hydrothermal activity area off the western coast of Kumejima Island. This submarine hydrothermal activity area is located in the caldera of a submarine volcano. Multiple plumes indicating intense hydrothermal activity were observed by acoustic surveys, and in addition, samples that appear to be fragments of chimneys formed in relation to submarine hydrothermal activity were collected. There were also several submarine volcanoes with similar calderas adjacent to this area of hydrothermal activity, and manganese oxide that appears to have been formed from hydrothermal activity was collected from some of these. No submarine volcanoes with caldera...