Abstract:
For seismic stations deployed on ice sheets, determining crustal structure using P wave receiver functions
can be difficult since ice reverberations may mask P-to-S (Ps) conversions from the crust-mantle boundary
(Moho). In this study, we assess the usefulness of S wave receiver functions (SRFs), which are not affected by
ice multiples, for investigating crustal structure beneath ice sheets by analyzing broadband seismic data
recorded across the Transantarctic Mountains (TAMs) and the East Antarctic (EA) craton. Clear S-to-P (Sp)
conversions from the Moho are obtained using standard SRF processing methods and are easier to interpret
than the corresponding Ps conversion on PRFs. When the Sp-S times are modeled together with 16–20 s
Rayleigh wave group velocities, we obtain Moho depth estimates of ~40–45 km for the EA craton,
consistent with average Precambrian crustal thickness found globally but ~9 km thicker than previously
reported estimates. A somewhat thinner crust (~35–40 km) is obtained beneath the TAMs, suggesting that
crustal buoyancy is at most a minor contributor to the uplift of the mountain range in this region.
