One of the best studied sites on the Juan de Fuca Ridge, a mid-ocean ridge spreading center off the northwestern coast of the US, is the Endeavor Ridge Segment. This area has been extensively mapped and sampled over the last 10 years by the NSF-funded Ridge 2000 Program whose objective is to dramatically advance our understanding of mid-ocean ridge magmatic, seismic, hydrothermal, and biological systems, how they behave, and how they are linked together. The funded project focuses on correcting navigation errors in sample/feature locations and compiling data from NSF and non-NSF funded cruises and studies to create a high resolution, integrated map of geological and geochemical features/attributes. The juxtaposition of these disparate datasets will enable big-picture, integrated thinking about how these important volcanic systems operate, will allow comparison of this area with other parts of the globe-encircling mid-ocean ridge system, and will illuminate the processes that control volcanism and hydrothermal venting at mid-ocean ridges. Broader impacts of the work include support of graduate and undergraduate students, a postdoc, and a PI whose gender is under-represented in the sciences.
Detailed multidisciplinary study sites require good spatial data to understand how all the different data types fit together. This project created such a base map at 1 and 4 meter resolution for thehydrothermal study site on the Endeavour mid-ocean ridge axis by merging high-resolution bathymetric data from different autonomous underwater vehicles (AUVs) into a bathymetric map that was then located in real latitude-longitude space using GPS-navigated surface ship lower-resolution bathymetric data. The high-resolution AUV bathymetric grid was used to: 1) map the distribution of sulfide chimneys, both active and inactive; 2) map the locations and extents of young lava flows; and 3) to map the distribution of fissures and faults along the ridge axis. In addition, we have evaluated; 1) the sizes, eruptive styles, geochemistry, and relative ages of lava flows, 2) the absolute ages of flows using radiocarbon in foraminifers from the base of sediment cores, 3) the locations of lava samples, and 4) the distribution of dated and undated sulfide chimneys and samples. The high-resolution bathymetry serves as the spatial base for numerous studies conducted over more than 25 years at this RIDGE program Intensive Study Site and the location of a node of Neptune Canada’s cabled observatory.
