A systematic search for mantle discontinuities using SS‐precursors

We perform a systematic search for reflectors in the upper and lower mantle using SS‐precursors. The largest number of robust reflections comes from a depth of 220 km, which we associate with the Lehmann discontinuity. This discontinuity is observed below both continental and oceanic areas, though the largest amplitudes appear beneath the continents. There is also evidence for weak discontinuities at approximately 260 and 310 km depth. The regions where we find the Lehmann discontinuity, in a global search, correspond to regions where local studies have found reflectors at similar depth. There are suggestions of lower mantle reflectors, in particular in the Indonesian subduction zone area where other studies have found similar reflections.