Volatile recycling at the Lesser Antilles subduction zone

The subduction water cycle is a key process for understanding the long-term evolution of surface water, arc volcanism, mantle hydration and convection. Seismic hazard may also be directly influenced by spatial variations in the hydration of the incoming plate. Much of our current understanding of these processes comes from studies in the Pacific where fast-spread oceanic lithosphere is subducted. In this talk I will present results from project VoiLA (2015-2021) – a NERC-funded large grant that targeted the Lesser Antilles subduction system in the slow-spread Atlantic. Using active-source seismology I will show that the Atlantic lithosphere is much wetter and more laterally variable than Pacific lithosphere. These results, when mapped onto the slab, show a clear correlation with mantle wedge properties obtained from passive-source seismology and arc geochemistry. Our ability to track volatiles through the system offers the potential to improve global budget estimates and local hazard assessment.