Sparse adaptive waveform inversion for rapid sub-basalt prospect identification

We show that it is possible to use low-cost, sparse, adaptive waveform inversion, operating at a maximum frequency of only 4 Hz, with an in-line shot spacing of 750 m, and only 10 iterations in total, applied to a narrow-azimuth, inclined towed-streamer dataset, to build a sub-basalt velocity model that is sufficient to identify high-porosity intra-basalt clastic targets beneath rugose basaltic overburden. The approach allows rapid identification of potential prospects from large legacy seismic datasets in basaltic provinces.