2007 Update

2007 Update (submitted April 2007, appended Nov. 2007)

A large segment of the ultraslow spreading ridge community met in fall 2006 in Sestri Levante, Italy at the InterRidge-European Science Foundation-funded "Polar Ridges Meeting and Workshop". During 3 days of talks, workshop and field trips, the main topics discussed were the cutting edge of ultraslow spreading ridge science, concrete plans for new expeditions on ultraslow spreading ridges, and new countries (notably China and Korea) who are interested in increasing their involvement in the study of ultraslow spreading and polar mid-ocean ridges. See Polar Ridges Workshop 2006 on the IR website: http://interridge.whoi.edu/WG/ultraslow/06PolarRidges.

Progress is being made about the role of thick-skinned rifting in the breakup of continents as well as the evolution of ultraslow spreading ridges. This is outlined in a new general review of ultraslow spreading ridges (Snow and Edmonds, 2007), and was a featured topic in a second meeting in 2006, the IODP Workshop on Continental Breakup held in September 2006 in Pontresina, Switzerland, near the site of the original outcrops on which the term 'ophiolite' was defined (http://www.iodp.org/continental-breakup).

Significant progress has taken place in investigation of the ultraslow Southwest Indian Ridge. An important contribution was made by Mathilde Cannat and colleagues, who reported on a pioneering study of off-axis morphology, tectonics and geophysics on the Southwest Indian Ridge (Cannat, et al., 2006). In early 2007, the first active high-temperature hydrothermal vent field was discovered at the Southwest Indian Ridge west of the Gallieni fracture zone by an international team of scientists on board the Chinese R/V DayangYihao using the ABE vehicle of the Woods Hole Oceanographic Institution (Tao et al., 2007).

This year, extensive under-ice AUV operations are planned by Rob Reves-Sohn and colleagues along the Arctic Gakkel Ridge, in order to better characterize the hydrothermal activity found there.

- Cannat, M., D. Sauter, V. Mendel, E. Ruellan, K. Okino, J. Escartin, V. Combier and M. Baala (2006) Modes of seafloor generation at a melt-poor ultraslow-spreading ridge. Geology v. 34; no. 7: 605-608.
- Snow J. and H. Edmonds (2007) Ultraslow Spreading Ridges: Rapid Paradigm Changes. Oceanography, Vol. 20, No. 1: 90-101.
- Tao, C., J. Lin, S. Guo, Y.J. Chen, G. W. X. Han, C.R. German, D.R. Yoerger, J. Zhu, N. Zhou, X. Su, E.T. Baker, and DY115-19 Science Party (2007) First discovery and investigation of a high-temperature hydrothermal vent field on the ultra-slow spreading Southwest Indian Ridge, EOS Trans. AGU, Fall Meet. Suppl., Abstract T52B-07.