HR: 16:06h
AN: V44A-02 INVITED     [Abstracts]
TI: Discoveries From the Cross-Disciplinary, Multi-Institutional South Seas Expedition from Hawaii to New Zealand and Back
AU: * Malahoff, A
EM: malahoff@hawaii.edu
AF: Univ of Hawaii & Institute of Geological & Nuclear Sciences, New Zealand, Hawaii Undersea Research Lab, 1000 Pope Rd, MSB 303, Honolulu, HI 96822 United States
AU: Wiltshire, J C
EM: johnw@soest.hawaii.edu
AF: Univ of Hawaii, Hawaii Undersea Research Lab, 1000 Pope Rd, MSB 303, Honolulu, HI 96822 United States
AU: Smith, J R
EM: jrsmith@hawaii.edu
AF: Univ of Hawaii, Hawaii Undersea Research Lab, 1000 Pope Rd, MSB 303, Honolulu, HI 96822 United States
AB: The Hawaii Undersea Research Laboratory organised an international research team to explore the chemistry, geology, biology, hydrothermal venting processes, mineral deposition, and biodiversity of seamounts extending south from Hawaii to New Zealand, including the submarine volcanoes of the Tonga-Kermadec Island Arc. Research team members came from a Consortium comprising of principal investigators from the NOAA Pacific Marine Environment Lab and VENTS program, the Inst of Geological and Nuclear Sciences and the National Inst of Water and Atmospheric Research both of New Zealand, the Univ of Kiel in Germany, the Univ of Mississippi, Univ of Hawaii, the NOAA Marine Fisheries Service, Scripps Institution of Oceanography, Univ of Oregon, Oregon State Univ, Stanford Univ, and the U.S. Fish and Wildlife Service. Funding came from the member organizations of the Consortium and the NOAA Office of Ocean Exploration and National Undersea Research Program. The expedition left Hawaii on 18 March 2005 and returned on 05 August, aboard the R/V Ka`imikai-o-Kanaloa with the submersibles Pisces IV and Pisces V and the ROV RCV-150. Sixty-one science dives were executed during the eight legs of the expedition. Twelve active volcanoes in the Samoa to New Zealand legs, one in the Samoan hot spot chain and the flanks of five islands and atolls on the legs between Samoa and Hawaii were investigated. Hundreds of specimens of new and unusual marine life, corals and other benthic organisms, extremophile micro- and macro-organisms, water samples for chemical analysis, polymetallic sulfides and rock samples were collected during the expedition. Unusual processes were observed at the Kermadec submarine volcanoes, including the oozing of liquid sulphur onto the seafloor and profuse carbon dioxide venting into seawater. Extensive submarine hydrothermal venting, black smoker activity and extraordinary chimney formations were studied in the caldera of Brothers Volcano. In addition, extensive communities of animals consisting of giant mussels, long-necked barnacles, pogonopheran worms, crabs, vent fish and mats of micro-organisms were mapped on the volcano flanks down to water depths of 2,000 m. Of note was that each active volcano maintained its own characteristic mix and dominance of animals. New species of life forms were detected and 27 new species of extremophile bacteria have been analysed. The active submarine volcano Vailulu'u in the Samoan chain was found to have a new 300-m high volcanic cone growing in its caldera that was not present when the edifice was last depth sounded in 2001. Turbid waters, hydrothermal activity and a ``Medusa'' rock full of eels were additional noteworthy discoveries. Assessment of living marine resources and habitat, collection of precious corals for dating to infer climate change and marine archaeology were the projects on the Samoa-to-Hawaii legs through the Line Islands. These were first exploration of these waters at depths below 200 m. The terrain was primarily sediment-scoured carbonate cliffs and escarpments, incised with box canyons and deeper chasms. The team consortium approach to a systematic study of these diverse submarine volcano and seamount settings ensured the operational and research success of this ambitious expedition.
UR: http://oceanexplorer.noaa.gov/explorations/05fire/welcome.html
DE: 3001 Back-arc basin processes
DE: 3017 Hydrothermal systems (0450, 1034, 3616, 4832, 8135, 8424)
DE: 3075 Submarine tectonics and volcanism
DE: 3080 Submergence instruments: ROV, AUV, submersibles
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005