Data Examples

Watson Company Inc. has developed advanced data processing techniques to reduce and analyze geophysical data. Correlation of multiple data sets provide insight into the geologic conditions. Descriptions and data examples are provided below.

The Full Spectrum Sub-bottom Profiler, commonly referred to as a “chirp”, provides extremely high resolution records utilized in data interpretation. Seafloor penetrations are subject to sediment types but are typically 5 - 20 meters, depending on the acoustic characteristics of sub-bottom materials. High quality sub-bottom data processing is important for engineering studies that require correlation of stratified lithology with soil boring data.

The channel shown above is approximately 750 meters wide and 6.5 meters deep.

Data from Full Spectrum Sub-bottom Profiler

CDP Multi-channel sub-seafloor interpretations are made from data that is digitally acquired and processed. Processing is directed at establishing whether an anomaly was due to source, processing or geology. Velocity scans, near trace displays, shot displays and migrations are conducted to resolve near surface conditions.

Processed Migration section from high resolution CDP Multi-channel data - Upper Cook Inlet, Alaska

Side Scan Mosaics provide an understanding of the seafloor characteristics and are the basis for the surficial features interpretation. The side scan sonar imagery (seafloor reflectivity) is affected by the density of the material on the seafloor. For instance, rock areas are much better reflectors than soft sediment covered areas. In general, coarser grained sediments generally produce stronger reflections than fine grained sediments.

Side Scan Sonar Mosaic showing soft sediments (low reflectivity),

hard sediments (high reflectivity) including sand waves and cobbles

Correlation of side scan sonar and sub-bottom profiler data sets are utilized in the interpretation of seafloor material types and are displayed below with side scan sonar data in top panel. The Holocene deposit on the sub-bottom profiler data pinches out against the older exposed Pleistocene deposit.

Side Scan Sonar and Sub-bottom data used in the correlation seafloor interpretations