This photograph was taken from the manned submersible Shinkai6500 during Dive 659 on the R/V Yokosuka cruise YK01-15 at the Kairei hydrothermal vent field (25°19.23′ S, 70°02.42′ E, 2450 m water depth), about 15 miles north of Rodriguez Triple Junction, Central Indian Ridge. The Kairei field is the first witnessed active hydrothermal field in the Indian Ocean, and is known to host extraordinary H2-rich fluids (Takai et al., 2004). The Kali chimney is the main vent of the field with temperatures above 360°C, accompanied by black particles of metal sulfide minerals precipitated by mixing with cold ambient seawater. A netting ball in lower left of this photograph is a part of a marker for deep-sea investigation, and the diameter of the ball is about 5 cm. The multidisciplinary research on this hydrothermal field and associating ecosystem provided key insights for the TAIGA PROJECT.
(Explanation: Hiromi WATANABE; Photograph: Courtesy of Ken TAKAI, JAMSTEC)
