Characterising ice slabs in firn using seismic full waveform inversion, a sensitivity study

Abstract The density structure of firn has implications for hydrological and climate modelling, ice-shelf stability. can be evaluated from depth models seismic velocity, widely obtained with Herglotz–Wiechert inversion (HWI), an approach that considers the slowness refracted arrivals. However, HWI is strictly appropriate only steady-state profiles accuracy compromised where contains ice layers. In these cases, full waveform (FWI) may yield more success than HWI. FWI extends capabilities by considering incorporates reflected Using synthetic profiles, assuming both steady- non-steady-state accumulation, we show outperforms detecting slab boundaries (5–80 m thick, 5–80 deep) velocity anomalies within firn. detect slabs thicker one wavelength (here, 20 m, a maximum frequency 60 Hz) but requires starting model to accurate ±2.5%. We recommend field practice shallowest layers are constrained ground-truth data. Nonetheless, shows advantages over established methods, should considered when characterisation goal survey.