The use of the combined seismic methods, sparker and boomer, allows to show different structures.
At same water depth, generally sparker will give better penetration than boomer.
Courtesy : Isabelle THINON
BRGM GEO GBS
Geology division Sedimentary basins unit
Same time scale of 10 ms grid (TWT) for both profiles.
The geology here is mostly sandy beds, in an area of shallow water depths of 10 m.
First, the boomer profile shows a fine resolution of 0.5 to 0.75 ms, obtained with a Seistec boomer from IKB.
Second, on the sparker profile, the sand layer bounderies, and the internal structures are visible.
Penetration is equivalent, due to the multiples and the shallow water depth.
Maximum energy output : 200 joules with an Energos energy source.
The boundaries of the sand layers, and the internal structures of the layers will be visible with the sparker method.
Penetration of 200 m in sands, for example, can be easily achieved with a sparker, provided the sufficient energy is applied. From 100 to sometimes more than 1000 joules can be necessary. But, the increase of power does not necessarily increase the penetration. More acoustic signal is reflected back off the seafloor, with multiple reflections masking the reflections inside the sea-beds.
Sand grains disperse the energy. This dispersion is variable with the thickness, the grain size, and the grain sorting.
This energy reflected by the seabed stratifications create the profile of marine sediments.