Volcanic eruptions at East Pacific Rise near 9°50′N



Evidence for recent volcanic eruptions along the fast spreading East Pacific Rise (EPR) crest near 9°50′N spanning about 4 to 5 months of activity was discovered in April and May 2006 as a result of studies related to the U.S. National Science Foundation' (NSF) Ridge2000 (R2K) program. In April, during routine recovery and redeployment of ocean-bottom seismometers (OBS) at the EPR R2K Integrated Study Site (ISS) near 9°50′N, eight of 12 OBS could not be recovered [Tolstoy et al, 2006]. Anomalous turbidity and temperature structure in the water column along the ridge axis confirmed scientists' suspicions that the OBS were trapped by a new lava flow.

A resurgence in magmatism recently had been postulated, based on temporal changes observed over the past few years in hydrothermal vent fluid chemistry and temperatures [Von Damm et al, 2004] and increasing microseismicity [Tolstoy et al, 2006].