Mid-ocean ridge eruption rates, long-term climate change, and the importance of marine seismoacoustics

Abstract

Recent work on mid-ocean ridges suggests that eruption rates may not be as steady-state as once thought. There is evidence that seafloor eruptive activity waxes and wanes with long-term climate cycles potentially both being driven by climatic forcings and possibly serving itself as a climatic forcing. An important piece of evidence in understanding mid-ocean ridge volcanic cycles is to look at present-day eruption rates and compare those with expected eruption rates given well-constrained plate spreading rates. However, given that mid-ocean ridge eruptions appear to be relatively infrequent, seismoacoustic coverage of as much of the ocean as possible is key. Work at Axial Seamount and the East Pacific Rise has documented an impulsive signal that is associated with lava erupting onto the seafloor. Thus with adequate marine seismoacoustic coverage, seafloor eruptions can be identified with some confidence without in situ confirmation. Such monitoring would provide for better quantification of present-day eruption rates in the marine environment and help understand the contribution of mid-ocean ridges to present-day volcanism, as well as possible long-term variability.