Arjun Datta , Shravan M. Hanasoge , Jeroen Goudswaard

We present a new method for determining the azimuthal variation of ambient seismic noise sources, that combines the computational speed and simplicity of traditional approaches with the rigour of waveform-inversion-based approaches to noise-source estimation. This method is based on a previously developed theoretical framework of sensitivity kernels for cross-correlation amplitudes. It performs a tomographic inversion for ambient noise sources on the Earths surface and is suitable for small (local) scale studies. We apply the method to passive seismic data acquired in an exploration context, and account for azimuth-dependent uncertainties in observed cross-correlation amplitudes. Our inversion results correlate well with the azimuthal distribution of noise sources suggested by signal-to-noise ratio analysis of noise cross-correlation functions.