These ‘‘standard’’ depth values most probably
do not correspond to the bottom-hit depth value but rather reflect
the result of the data processing. For all probe types, higher bin
percentages are also observed in some vicinity of the respective
nominal maximum sample depth, reflecting the wire-break limit
depth rather than the bottom hit. Thus, we excluded from the
analysis all XBT casts with the last sample depth exceeding 198 m
for T10 probes, exceeding 445 m for T4, T6, and SX group, and
exceeding 745 m for T7, DB, and DX group. To further minimize
the effect of the highly erroneous bottom-hit and/or GEBCOdepth values, casts are only considered for which the depth
difference satisfies 9DGEBCO–DXBT9o100 m (DGEBCO and DXBT
represent GEBCO bottom depth and the last sampled XBT level
in meters).