Mapping Top of Rock and Sediment Thickness

San Felipe, Panama

A port expansion was planned off the coast of San Felipe, Panama. GeoView was tasked to provide bathymetric information within the survey area, map the top of rock and evaluate the thickness of the overlying marine sediments. The survey area was approximately 300 hectares in size. GeoView collected sub-bottom profiling and bathymetry data along transect lines spaced approximately 25 meters on center. The sub-bottom data was collected using an Edgetech 3200 system with a 216 towfish for the sub bottom portion. The Edgetech system is a full Spectrum CHIRP imaging system. A frequency range of 2-16 kHz was used.

During the survey, the towfish was positioned 1 meter below the surface of the water. The high-power, low-frequency system was able to penetrate deep in to the marine sediment and map the top of rock to depths of 20 meters. The bathymetry data was collected using an ODEM Echotrac CVM. The Echotrach system uses a high frequency (200 Kilohertz (kHz)) transducer which was towed at a depth of 0.5 meters below the surface of the water. The high frequency and rapid pulse rate enabled accurate mapping of the seafloor. The data was processed using Hypack© and SonarWiz.Map©. Contour maps of the elevation of the seafloor, the thickness of the marine sediement, and elevation of the top of rock were produced.

Example of Sub-Bottom Data Profile Collected at the Project Site using an Edgetech 216