Dynamics of Deep-sea Volcanic Eruptions
Geology & Geophysics
Woods Hole Oceanographic Institution
More than two-thirds of the Earth's volcanic output occurs in the ocean basins, much of it along the global mid-ocean ridge system. As no active mid-ocean ridge eruptions have been directly observed, our knowledge of eruption dynamics (eruption rates, flow velocities) in this environment are extremely limited. Eruption dynamics represent a primary parameter controlling length scales of volcanic deposition and provide some of the best indicators of the state of crustal magma storage reservoirs. In this talk, Adam Soule will describe a novel geospeedometer for mid-ocean ridge eruptions, CO2 degassing and vesiculation, that can constrain eruption duration and flow rates. This is accomplished through detailed seafloor mapping coupled with analysis of dissolved and exsolved volatile constituents in seafloor basaltic glasses. Volatile concentrations and vesicle properties are used to constrain dynamic models of degassing and provide estimates of flow duration and time/distance-dependent flow rates. These results provide a framework in which to evaluate global-scale variability in eruption dynamics and refine our understanding of MOR carbon flux.
Adam Soule began his research career firmly on land, studying volcanic processes on active and historic Hawaiian eruptions through field-based studies, remote sensing, and petrologic studies of samples. In 2003, he joined WHOI as a post-doctoral scholar and has since focused his research on volcanic and tectonic processes in the deep ocean. He has participated in ~20 research cruises and used a variety of deep-submergence vehicles (HOV: Alvin, Nautile; ROV: JasonII, Doc Ricketts; AUV: Sentry; Deep-towed sonars: DSL120, IMI30) to conduct his research. His research has been conducted on the East Pacific Rise, Mid-Atlantic Ridge, Gakkel Ridge, Guaymas Basin, and Kermadec Arc. His research interests lie at the intersection of seafloor geology/morphology, geochemistry, and shallow geophysics and are aimed at answering questions related to the interplay between magmatism, tectonism, and hydrothermal circulation in the development of oceanic crust.