Estimating the Rayleigh-wave impulse response between seismic stations with the cross terms of the Green tensor

The development of ambient noise tomography has provided a powerful tool to investigate the Earth's subsurface with increased resolution. Most commonly, surface-wave tomography is performed on inter-station estimates of the vertical component of Rayleigh waves, stemming from crosscorrelations of ocean-generated noise. Here, we estimate the cross terms of the Rayleigh-wave Green tensor, and show this is less sensitive to signal not in-line with the seismic stations. We illustrate this result with the Batholiths temporary seismic deployment, showing estimates of the Rayleigh wave with a higher signal-to-noise ratio and a consequently better phase-velocity dispersion curve. This approach provides an opportunity for reliable ambient noise crosscorrelations over shorter time windows and more closely spaced stations in the future.