Led by: Andrew Fisher, University of California Santa Cruz
Integrated Ocean Drilling Program (IODP) Expedition 327 (July 5 – September 4, 2010) and subsequent UNOLS follow-up cruises are parts in a series of long-term multidisciplinary experiments that build from technical and scientific achievements and lessons learned during Ocean Drilling Program (ODP) Leg 168 and IODP Expedition 301, on the eastern flank of the Juan de Fuca Ridge.
The Juan de Fuca Ridge flank (JdF) major program is exploring the nature of linked hydrogeologic, geochemical, and microbiological conditions and processes in a region that is the best understood example of ridge-flank hydrothermal circulation on the planet. In this setting, a volcanic crustal aquifer contains highly altered (suboxic to anoxic), warm (64 °C) hydrothermal fluids that are isolated from the overlying ocean in most locations by hundreds of meters of hemipelagic sediment and turbidites. Projects using data and field samples from this region have included two IODP expeditions (301 and 327); long-term borehole observatories (CORKs) used for testing, monitoring and sampling; and numerous non-drilling oceanographic expeditions using oceanographic ships and submersibles/ROVs, laboratory studies using materials and associated microbial cultures, and theoretical and computational experiments. Tools and methods developed for the JdF program have been adapted and applied at other sites, including other C-DEBI major program locations. The JdF major program has contributed to training of numerous graduate and undergraduate students and other junior researchers, including those who add diversity to the STEM pipeline; has linked researchers and students from across the US and around the world, who work on common technical and scientific goals; and has comprised the basis for several successful education and outreach programs to the K-12 community and the public at large. More specifically, the JdF major program has explored these and related questions:
- What are the rates, directions, and distributions of fluid and coupled energy, solute, and microbial processes within the volcanic crustal aquifer?
- How do microbial populations in the volcanic crust differ from location to location, and from those found in the overlying ocean and sediments?
- How do microbial processes contribute to rock and fluid alteration?
Answering these and related questions will help to achieve goals important to Phase 2 of C-DEBI, within all three of the new program themes (Connectivity and Fluxes, Activities and Communities, Metabolism and Survival).