The 2005-06 eruption of the EPR at 9-10N: Insight into fast-spreading ridge volcanic processes

Abstract:In late 2005-early 2006 an eruption occurred along the crest of the East Pacific Rise in nearly the same location as the previous known eruption at this site (1991-92). Numerous towed camera surveys, a deep-towed sidescan sonar survey, and several submersible/ROV dives have allowed us to produce the most detailed map of a fast-spreading ridge eruption produced to date. We establish the timing of the eruption using physical and geochemical methods and examine the size of the eruption relative to past events along the ridge crest. Through comparison with the wealth of high-resolution data and observations at this site, we are able to examine the eruption processes that controlled the deposition of lava including focusing of lava flows by pre-existing topography and lava channels, interaction with faults, and relationship to fine-scale ridge crest segmentation. The 2005-06 eruptive event allows us to test the conceptual models of ocean crust construction that have been developed by examining the products of past eruptions and establish the baseline data to examine future change at this volcanically, tectonically, and hydrothermally active mid-ocean ridge segment. ------------------------------------------------------------------------------------------ Séminaire Géosciences Marines ------------------------------------------------------------------------------------------