HR: 1330h
AN: B12A-0730 INVITED     [PDF]
TI: The East Pacific Rise 8\deg to 11\deg N Integrated Studies Site (ISS); Update and Opportunities
AU: * Carbotte, S
EM: carbotte@ldeo.columbia.edu
AF: LDEO, 61 Rte 9W, Palisades, NY 10964 United States
AU: Haymon, R
EM: haymon@geol.ucsb.edu
AF: Department of Geological Sciences, University of California Santa Barbara, Santa Barbara, CA 10964 United States
AU: Holland, M
EM: Melanie.Holland@asu.edu AF: Department of Geological Sciences, Arizona State University, Tempe, AZ 85287 United States
AU: Von Damm, K
EM: kvd@eos.sr.unh.edu
AF: Complex Systems Research Center, University of New Hampshire, Durham, NH 03824-3525 United States
AB: The 8\deg to 11\deg N segment of the East Pacific Rise (EPR) represents a dynamic, fast-spreading type of mid-ocean ridge selected for focused interdisciplinary study within the Ridge 2000 program. Diverse fast spreading environments are encompassed by the site including a hierarchy of axial segments and discontinuities. The site "bull's- eye" is at 9\deg49' to 9\deg51' N where numerous high temperature vents and diffuse flow communities have been mapped and monitored over the past 14 years. Concentric circles around the bull's eye encompass ridge segments at a range of scales, from the first-order segment bounded by the Siquieros and Clipperton transform faults to the fourth-order segment which includes the extent of the 1991 and 1992 volcanic eruptions. Five-year goals for the site include a working model of mantle flow and melt supply; detailed imaging of subseafloor structures and relationships to vent communities and chemistry; quantitative data about microbes and macrofauna and linkages with fluid flow, tectonics, and magmatism; quantification of the heat/chemical flux into the water column; and linkages and temporal variation in geological, chemical, and biological parameters. Field programs in 2002 collected data for calculations of primary and secondary productivity at different vent communities, with a focus on tube worms and bivalves; searched for hydrothermal signals from an earlier earthquake swarm; and continued time-series fluid sampling at all 9\deg10' to 9\deg51'N high-temperature vents. 2003 cruises will continue geophysical/volcanological studies and deploy an array of in situ chemical sensors for use in monitoring vent fluids. Programs scheduled to begin in 2004 include three-dimensional multi-channel seismic and magnetotelluric studies of subsurface structure at the site "Bull's eye", initiation of monitoring studies of seismicity, fluid temperature and chemistry, and vent fauna. An overview of on-going and upcoming studies at the site will be presented.
DE: 3035 Midocean ridge processes
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 8150 Plate boundary--general (3040)
SC: Biogeosciences [B]
MN: 2003 Fall Meeting