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. The 2-m pixel sidescan mosaic, when compared with a pre-eruption sidescan imagery collected with the same instrument in 2001 (Schouten, Fornari, Tivey - WHOI) reveals significant changes to the seafloor in the eruption area. The previous volcanic structure of the ridge crest, as indicated by variations in acoustic texture, has been overprinted by new lobate and sheet flows including numerous new lava channels emanating from the axial summit trough and feeding flows that reached up to 2 km from the axis.
Observations and samples of lava from the 2005-2006 eruptions were collected by Jason2 during a 3-day ROV dive. Several near-bottom high resolution multibeam surveys over the axial summit trough and installation of navigation benchmarks at 4 sites were also conducted during the dive. The field work was funded by the National Science Foundation's Ridge2000 Program.
