In October 2003 a 4 x 4 km ocean bottom seismometer (OBS) array was deployed at 9°50'N on the East Pacific Rise as part of the Ridge 2000 Integrated Studies Site program. This site had been intensively studied since a very recent eruption was fortuitously discovered there in 1991. The OBS array monitored through January 2007, with approximately annual turn-arounds, capturing an eruption in January 2006 preceded by a two-year long ramp up in activity rates. Analysis of data from the 2003-2004 deployment data reveals thousands of tiny cracking events that appear to illuminate a hydrothermal circulation cell. The geometry of the hydrothermal circulation is consistent with long term fluid chemistry and temperature measurements made since 1991, and reveals how such systems may evolve from eruption to eruption. The results emphasize the importance of long-term monitoring to understanding fundamental seafloor processes.