资源环境科技发展态势分析平台

Reflection profiles generated using PKPdf as a virtual source show laterally continuous reflections from structures at depths less than 1 km to roughly 200 km beneath the southern Appalachian orogen and Atlantic Coastal Plain. Arrivals interpreted as reflections from the Moho increase in time from ~10 s beneath the Coastal Plain to 17.4 s (~57 km) beneath the Blue Ridge Mountains, providing additional evidence that the southern Appalachians are in rough isostatic equilibrium. Reflections at 32‐36 s (120‐135 km) are consistent with the depth to the base of the lithosphere found in recent inversions of Ps arrivals and surface waves. Alternatively, these and later reflections at times up to 58 s (~224 km) may be due to layering associated with drag‐induced flow in the asthenosphere, suggesting largely horizontal rather than vertical flow for depths less than 225 km beneath the Georgia coastal plain.