In August-September 2008, the third leg of the 2008 Chinese DY115-20 expedition on board R/V DayangYihao has successfully discovered, for the first time, active hydrothermal vent fields on the fast-spreading Southern East Pacific Rise (SEPR) near the equator. This expedition follows the work of a 2005 expedition by R/V DayangYihao, during which water column turbidity anomalies were measured in the region.

The InterRidge Office would like to highlight an Australian research cruise currently underway in the northern Lau Back-arc Basin (NLB). The SS07-2008 cruise, led by Chief Scientist Richard Arculus from Australian National University, will be in two legs from 30 April - 7 June 2008 on R/V Southern Surveyor. The objective of the first leg will be to survey the bathymetry, magnetic characteristics, petrology, hydrothermal activity, and hence origins and evolution of two of four spreading centers within this region (Northwest Lau [NWLSC] and Niuafo’ou [NSC]), which are essentially unstudied.

The InterRidge Office has just received news from a January 2008 cruise on board R/V Hakuho-maru to the Southwest Indian Ridge near the Marion hotspot. We thank Dr. Nobukazu Seama, InterRidge Steering Committee Member from Japan, for providing a summary of the cruise objectives and sampling. Please visit the InterRidge-Japan webpage for ship track and sampling locations:
http://ofgs.ori.u-tokyo.ac.jp/~intridgej/report_html/KH07-4-2/KH07-4-2.htm

FIX08: An interdisciplinary and international collaboration to study autotrophic carbon fixation and fluid chemistry at 9ºN and 13ºN EPR

An international group of scientists representing five different countries, i.e., USA, Germany, France, Italy, and China, was recently on board R/V Atlantis on cruise AT15-28, named FIX08. They were conducting work on in-situ chemistry of high- and low temperature hydrothermal vent fluids and the characterization of microbial communities carrying out autotrophic carbon fixation.

The latest Dive and Discover expedition recently took place along the Southern Mid-Atlantic Ridge (Cruise dates: Dec. 31 - Jan. 17, 2008). Kristen Kusek, InterRidge's Education & Outreach Coordinator, was the science writer for the cruise. The team tested state-of-the-art communications technology on a hunt for hydrothermal vents using two new AUVs, Puma and Jaguar. Hop aboard and watch the action!

The InterRidge Office has received news from a U.S. research cruise at the East Pacific Rise 9ºN Integrated Studies Site. The LADDER III cruise, led by Chief Scientist Lauren Mullineaux from Woods Hole Oceanographic Institution, is underway (13 Nov - 3 Dec 2007) on R/V Atlantis with the research submersible Alvin. LADDER is an acronym for LArval Deep Dispersal on the East Pacific Rise.

Four new hydrothermal sites on the Southwest Indian Ridge and the Central Indian Ridge located by Chinese DY115-19-Leg 3 cruise

After discovering the first black smoker at the ultraslow spreading Southwest Indian Ridge (SWIR), Chinese R/V Dayang Yihao continued its expedition with the third leg across the Indian Ocean. The leg started in Durban, South Africa on 15 March 2007 and finished in Fremantle, Australia on 24 April 2007. This 39-day leg was funded and sponsored by China Ocean Mineral Resources R & D Association (COMRA) and led by Dr. Xiqiu Han, Second Institute of Oceanography, SOA. The objective of this leg was mainly to look for new active hydrothermal sites along the ultraslow spreading segment of the SWIR and the moderately-fast spreading segment of the Central Indian Ridge (CIR).

July 1 - August 10 2007
Longyearbyen, Svalbard to Tromso, Norway
MV Oden

AGAVE was a multi-disciplinary expedition with the primary purpose of finding and characterizing hydrothermal vent fields along ice-covered portions of the Gakkel Ridge.

Integrated studies at the Lucky Strike vent fields (MoMAR)

V. Ballu1, W. Crawford2, J. Escartin2, P.-M. Sarradin3 and Science Parties*

The 2nd leg of the MoMARDREAM-Naut cruise (19-28 July 2007) onboard "PourQuoi Pas?" (IFREMER/SHOM) with the submersible Nautile (IFREMER) will carry out multidisciplinary and integrated studies at the Lucky Strike hydrothermal site. Additional field work will be carried out onboard "Suroit" (IFREMER) during BBMoMAR (18-28 July 2007). This 2007 field work is part of a coordinated effort within the French MoMAR program to monitor active processes and their feedback at a slow-spreading segment, and it is funded primarily by CNRS, INSU and IFREMER.

The MoMARDREAM-Naut Leg 1 cruise (8 - 19 July 2007) was the first part of the multidisciplinary project MOMARDREAM lead jointly by Jérôme Dyment (IPGP-Paris), Françoise Gaill (CNRS-Université Paris 6) and Yves Fouquet (IFREMER). The first 9 Nautile dives were dedicated to the biology and geology of the Rainbow site at the Mid-Atlantic Ridge (MAR). Françoise Gaill was the chief scientist and Jérome Dyment the project leader.

R/V Hakuho-maru at the Central Indian Ridge

The KH-06-4 Research Cruise by R/V Hakuho-maru was conducted from 7 December 2006 to 5 January 2007, in the Central Indian Ridge. The research proposal was prepared by K. Tamaki, T. Ura, T. Gamo and others. We principally focused on advancing the understanding of the Rodriguez Segment (Segments 15 and 16) of CIR (the Central Indian Ridge) where the previous geological and geophysical studies were ongoing as UK and French programs. We conducted four operations; geophysical mapping by SeaBeam, magnetics, and gravity, AUV (Autonomous Underwater Vehicle) dives, CTD hydrocasts, and rock samplings. The principal results of the cruise are summarized as follows.

EPR 9˚50'N Ridge2000 ISS Summary

In March-April 2007, S. White (U. South Carolina) and A. Soule (WHOI) conducted a near-bottom sidescan sonar survey using the WHOI-NDSF 120 kHz deep-towed DSL120a system over the site of the 2005-2006 eruptions near 9˚50'N along the East Pacific Rise crest.

RRS James Cook on the Mid Atlantic Ridge

Roger Searle, Chris Macleod and Bramley Murton are leading the first cruise of the new UK vessel RRS James Cook, funded by the UKIODP programme, to the Mid-Atlantic Ridge near 15ºN. This is an area of extensive peridotite outcrop, and is perhaps the best known example at present of a so-called low-magmatic ridge. It was drilled by ODP Leg 209 in 2003, partly following recommendations from the InterRidge Meso-Scale Workshop report on 4‑D Architecture of the Oceanic Lithosphere (1993) and the subsequent workshop on Oceanic Lithosphere and Scientific Drilling into the 21st Century (1996), which was co-sponsored by InterRidge.

InterRidge China Update: Chinese Research Cruises Discovered the First Active Hydrothermal Vent Field at the Ultraslow Spreading Southwest Indian Ridge

Two recent Chinese research cruises on board Chinese R/V DayangYihao have successfully discovered the first active hydrothermal vent field at the ultraslow spreading Southwest Indian Ridge and collected hydrothermal sulfide deposit samples from the vent sites. The newly discovered hydrothermal vent field is in the central eastern portion of the Southwest Indian Ridge and is located on the western end of a magmatically robust spreading segment. These cruises were funded and sponsored by the China Ocean Mineral Resources R & D Association (COMRA) and were conducted on the 105-meter-long R/V DayangYihao.