HR: 17:15h
AN: V54A-06    [Abstracts]
TI: Geomicrobiological exploration and characterization of novel deep-sea hydrothermal activities accompanying with extremely acidic white smokers and elemental sulfur chimneys at the TOTO caldera in the Mariana Volcanic Arc
AU: * Takai, K
EM: kent@jamstec.go.jp
AF: SUGAR Project/JAMSTEC, 2-15 Natsushima-cho, Yokosuka, 237-0061 Japan
AU: Nakagawa, T
EM: n-takko@ganko.tohoku.ac.jp
AF: SUGAR Project/JAMSTEC, 2-15 Natsushima-cho, Yokosuka, 237-0061 Japan
AU: Suzuki, Y
EM: yohey@jamstec.go.jp
AF: SUGAR Project/JAMSTEC, 2-15 Natsushima-cho, Yokosuka, 237-0061 Japan
AU: Hirayama, H
EM: hirayamah@jamstec.go.jp
AF: SUGAR Project/JAMSTEC, 2-15 Natsushima-cho, Yokosuka, 237-0061 Japan
AU: Kosaka, A
EM: akosaka@ep.sci.hokudai.ac.jp
AF: Hokkaido University, N10W8 Kita-ku, Sapporo, 060-0810 Japan
AU: Tsunogai, U
EM: urumu@ep.sci.hokudai.ac.jp
AF: Hokkaido University, N10W8 Kita-ku, Sapporo, 060-0810 Japan
AU: Gamo, T
EM: gamo@ori.u-tokyo.ac.jp
AF: ORI, 1-15-1 Minamidai, Nakano-ku, Tokyo, 164-8639 Japan
AU: Nealson, K H
EM: knealson@usc.edu
AF: SUGAR Project/JAMSTEC, 2-15 Natsushima-cho, Yokosuka, 237-0061 Japan
AU: Horikoshi, K
EM: horikok@jamstec.go.jp
AF: SUGAR Project/JAMSTEC, 2-15 Natsushima-cho, Yokosuka, 237-0061 Japan
AB: Novel hydrothermal activities accompanying effluent white smokers and elemental sulfur chimney structures at the northeast lava dome of the TOTO caldera depression in the Mariana Volcanic Arc were explored by the manned submersible Shinkai 6500 and characterized by geochemical and microbiological surveys. The white smoker hydrothermal fluids were observed in the potential hydrothermal activity center of the field and represented a maximal temperature of 172 degree C and a lowest pH of 1.59, that was the lowest pH of the hydrothermal fluid ever recorded. The chimney structures consisting all of elemental sulfur (sulfur chimney) were also peculiar to the TOTO caldera hydrothermal field in the world. The geochemical characterization strongly suggested that the TOTO caldera hydrothermal field was a novel system driven by subseafloor mixing between the oxygenated seawater and the superheated volcanic gasses. Microbial community structures in a sulfur chimney structure and its formation hydrothermal fluid with a high concentration of hydrogen sulfide (15 mM) were investigated by culture-dependent and _|independent analyses. Ribosomal rRNA gene clone analysis and fluorescence in situ hybridization (FISH) analysis revealed that epsilon-Proteobacteria, specifically classified into Group G and Group B, dominated the microbial communities in the sulfur chimney structure and formed a dense microbial mat covering the sulfur chimney surface. Archaeal phylotypes were consistently minor components in the communities and related to the genera Thermococcus, Pyrodictium, Aeropyrum, and the uncultivated archaeal group of Deep-sea Hydrothermal Vent Euryarchaeotal Group. Cultivation analysis suggested that the microbial components inhabiting in the sulfur chimney structure might be entrained by hydrothermal fluids from the potential subsurface habitats
DE: 8424 Hydrothermal systems (8135)
DE: 8135 Hydrothermal systems (8424)
DE: 0400 Biogeosciences
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting