Ultra-slow Spreading Ridges

Objective: Ultraslow spreading ridges (<20mm/yr full spreading rate) represent a class of divergent plate boundary that possesses quite different geological, physical and chemical characteristics than slow, intermediate and fast spreading ridges. In addition, most of the ultraslow spreading ridges are found in polar or near-polar regions, including the circum-antarctic plate boundary and the Arctic spreading system. This class of mid-ocean ridges thus poses an interrelated set of unique scientific and logistical problems, but promises unusual benefits and insights into the workings of all mid-ocean ridges.

Themes: Lithosphere/Asthenosphere interaction; Magma genesis and mantle composition; Hydrosphere/Lithosphere interaction; Biogenesis; Biogeography

Chair - Jon Snow (University of Houston)

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.

Bibliography of ultraslow spreading-related papers

Download PDF compiled through 2005 Here

List below includes articles through 2008 (not comprehensive)

Baker, E.T. et al., 2004. Hydrothermal venting in magma deserts; the ultraslow-spreading Gakkel and Southwest Indian Ridges. Geochemistry, Geophysics, Geosystems - G (super 3), vol.5, no.8, 29 pp., 18 Aug 2004.
Brozena, J.M. et al., 2003. New aerogeophysical study of the Eurasia Basin and Lomonosov Ridge; implications for basin development. Geology (Boulder), vol.31, no.9, pp.825-828, Sep 2003.

Polar Ridges Workshop 2006

Sestri Levante, Italy
19-22 September 2006
Workshop Report

By Jonathan Snow, Henry Dick, Elisabetta Rampone, Colin Devey

In recent years, Polar mid-ocean ridges have been the focus of some of the most exciting scientific results from mid-ocean ridges globally. 60 scientists from the international mid-ocean ridge community met in the Italian coastal town of Sestri Levante for four days in mid-September, 2006 to discuss the progress and future of research on polar mid-ocean ridges. These include the trans-Arctic Gakkel Ridge and the circum-Antarctic SW Indian and American-Antarctic ridges. These mid-ocean ridges belong primarily to the ultraslow class of mid-ocean ridges (<16 mm/yr full spreading rate). Ultraslow ridges have gained increased recognition in recent years because of the very successful exploration of the Arctic ridge system by a number of cruises since the drafting of the InterRidge Arctic Mapping and Sampling Plan in 1998 (ref). Since then, we have seen the first intentional hard rock sampling in pack ice (Jokat, 1999; Snow, 2001), mapping by submarine beneath the arctic ice (Edwards 1999) an extensive program of mapping and sampling on Gakkel Ridge (Michael, 2003; Jokat; 2003; Edmonds 2003), and on Lena Trough (Snow, 2006).