Received: 19 March 2018
Accepted: 27 July 2018
First Online: 24 August 2018
: KA is the Deputy Director of the Research Institute of Geology and Geoinformation (IGG), the Geological Survey of Japan (GSJ) of the National Institute of Advanced Industrial Science and Technology (AIST). TI and TS are senior researchers in the Marine Geology Research Group in the IGG and experts on seismic reflection surveys. All authors are members of the “Geological Mapping Project Around Okinawa Islands.”
: The authors declare that they have no competing interests.
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