A new submarine volcano has been discovered offshore Mayotte, a part of the Comoros volcanic archipelago located between Africa and Madagascar. Regarding this seismo-volcanic activity, a 3-D passive tomography was conducted, in order to determine the structure of the volcanic plumbing system (Foix et al., 2021). Using > 3,000 earthquakes from an ongoing monitoring effort, and a 1D velocity model determined onboard, we jointly inverted for velocity structures, earthquake locations, origin times, and station corrections using LOTOS software . We are sharing here the 3-D P and S velocity models and 3-D output earthquake locations.