The thickness of subsurface layers if they had remained as they were prior to compaction may be estimated by restoring the volume of void space lost during compaction. Decompacted depths below seafloor, the depths the layers would be if compaction had not occurred, may be determined for the layers. A surrogate decompaction velocity may then be determined by dividing the decompacted depths by the travel times of acoustic waves that reflect off layers within the subsurface region. The decompaction velocity may be used in post-processing of acoustic data to produce a decompacted digital representation of the subsurface region. The decompacted digital representation may be used to directly interpret the thickness of layers prior to compaction, sedimentation rates over time, fault offsets, and other phenomena distorted by compaction.