Seismic Monitoring of the East Pacific Rise Ridge 2000 Integrated Studies Site

In September 2003 a closely spaced array of twelve ocean bottom seismometers will be deployed within the 'bull's-eye' region of the R2K ISS at 9deg49'N - 9deg51'N on the East Pacific Rise as part of the Ridge 2000 Integrated Studies Site. The array is to be deployed for approximately three years, with annual turn-around cruises. We plan to address a number of fundamental scientific questions, both seismic and interdisciplinary. We expect to study the character of near-axis faulting, to map the seismically active hydrothermal system, to look for tidal triggering of seismicity, and to determine the seismic character of magmatic activity should any be observed. We will make use of the latest advances in earthquake location methodology by computing highly accurate relative locations using the double-difference technique to remove model errors and waveform cross correlation to reduce pick uncertainties. This program is tightly coordinated with the fieldwork of other multidisciplinary monitoring in the area, which will provide an unprecedented opportunity to understand mid-ocean ridge system linkages. We hope to help document links between the seismicity, the hydrothermal system and the associated biology and provide a rigorous understanding of the significance of seismic activity to the mid-ocean ridge system. We will present a detailed outline of the experiment plans, as well as our plans to integrate and share the data collected. Details will also be presented of the deployment cruise including imaging of the 9deg50'N area.