Type of publication
Article in journal
Year of publication
Geophysical Journal International

Dirk Philip van Herwaarden, Michael Afanisiev, Solvi Thrastarson and Andreas Fichtner


van Herwaarden, Dirk Philip, Afanasiev, Michael, Thrastarson, Solvi and Fichtner, Andreas. Evolutionary full-waveform inversion. Geophysical Journal International. 2020. https://doi.org/10.1093/gji/ggaa459


Short summary
We present a new approach to full waveform inversion (FWI) that enables the assimilation of datasets that expand over time without the need to re-invert all data. This evolutionary inversion rests on a re-interpretation of stochastic L-BFGS, which randomly exploits redundancies to achieve convergence without ever considering the dataset as a whole. Specifically for seismological applications, we consider a dynamic mini-batch stochastic L-BFGS, where the size of mini-batches adapts to the number of sources needed to approximate the complete gradient. As illustration we present an evolutionary FWI for upper-mantle structure beneath Africa. Starting from a 1-D model and data recorded until 1995, we sequentially add contemporary data into an ongoing inversion, showing how (i) new events can be added without compromising convergence, (ii) a consistent measure of misfit can be maintained, and (iii) the model evolves over times as a function of data coverage. Though applied retrospectively in this example, our method constitutes a possible approach to the continuous assimilation of seismic data volumes that often tend to grow exponentially.