Japanese submersible explores the North Fiji Basin


  • J. -M. Auzende,

  • T. Urabe,

  • M. Tanahashi,

  • E. Ruellan,

  • Shipboard Scientific Party


Since 1987, Japanese and French geologists, geophysicists, and biologists have been studying the North Fiji Basin Ridge within the framework of a joint project named STARMER (Science and Technology Agency of Japan—IFREMER of France). This ridge was first geologically, geophysically, and geochemically surveyed during the 1985 SEAPSO 3 cruise of the R/V Jean Charcot [Auzende et al., 1988]. At that time, water sampling and morphotectonic analysis indicated that the North Fiji Basin Ridge was technically and hydrothermally active. Within the STARMER project, four surface ship cruises have been conducted {Kaiyo 87-88-89 and Yokosuka 90).

One significant result of these surveys is the complete mapping of the entire ridge between 14°S and 22°S (Figure 1), an area approximately 900 km long and more than 50 km wide (Sea Beam and Furuno multibeam swath-mapping systems were used). During the Kaiyo 87 cruise, the presence of active hydrothermalism (sulfide deposits, chimneys expelling shimmering water, and associated living animal colonies) was discovered through water sampling and video deep towing.