Multi-station inversion of P-wave receiver functions at Erebus volcano, Antarctica

Erebus volcano is a 1.3 My old stratovolcano on Ross Island in the McMurdo Sound off the coast of Antarctica. The volcano is one of the most active volcanoes on the Antarctic continent with Strombolian eruptions and a complex magmatic structure with a long-standing lava lake. Despite significant forays in shallow active source tomography and icequake based scattering imaging, the deeper structure of the Erebus volcano conduit system including crust and mantle transitions are still only sparsely resolved. Using the dense ETB-ETS and MEVO seismic deployments (2007-2009) with a total of 28 stations distributed broadly on the Erebus edifice, we compute high fidelity P-wave receiver functions (PRF) with stacks with an average of 28 earthquakes and invert them for structure. As often noted for PRFs computed over layered low-velocity structures such as ice sheets and sedimentary basins, the Erebus edifice produces a number of strong shallow scattering effects that distort some of the receiver functions. As such, we perform a multi-station MCMC inversion that assumes that the deeper crustal structures are sampled uniformly across stations, but significantly loosen those restrictions for the top few kms of the model where more local and path dependent scattering effects are expected. We then report on the general structure of the Moho under Erebus and discuss implications for its hot spot magmatism.