Sub-bottom profiling (SBP) with the StrataBox 3510 HD revealed relatively heterogeneous surface substrate with boulder and reef formations throughout the initial proposed location. A zone west of the initial location was identified as more suitable with approx. 50 by 30 m cover in minimum of 800 mm sand and no boulder or reef structure.
To further characterize the benthic surfaces within the survey area, a series of transects were undertaken using a sub-bottom profiling system. Geo referenced, sub-bottom data was acquired using an acoustic profiling system (StrataBox 3510 HD, SyQwest Inc., Cranston, RI, USA) operating at 10kHz.The use of the 10kHz channel was optimal due to the shallow water survey settings, and the requirement for high resolution sediment profile. Differences in acoustic impedance (sediment layering) were examined to detect surface expression of boulder and reef formations as well as determine the sand thickness layer. Transects were focused on mapping the potential placement site as well as a single transect along the proposed cable route.
Physical coring samples were taken to cross reference the sediment profile results of the Stratabox HD Survey.
Above is geometric graph that represents the sub-bottom survey lines and locations of sediment core sampling.