oa Time-Lapse Imaging of the Shallow Subsurface at Decimetre Scale Resolution

High-resolution seismic data provides information for many applications including offshore engineering work, where an accurate characterisation of the shallow marine subsurface is essential. However, single 3D volumes only provide a temporal snapshot and do not fully capture the highly dynamic nature of shallow water environments. Although changes at the seabed can be interpreted from repeat bathymetry, only very limited information about the substrate below. Here, we discuss the application of multiple, collocated, ultra-high-resolution (kHz-range) 3D seismic surveys as a tool to investigate changing processes in the marine subsurface. Examining data acquired with the 3D Chirp sub-bottom profiler, two case study examples will be presented. Results illustrate the capability for quantitative mapping of subsurface differences at decimetre-scale resolution using bin sizes of 0.25 cm and smaller.