4 Seismic data
analysis
4.1 Reflection data processing
The overall quality of the data is reasonable given the high noise level
background in the region, with a CMP fold coverage between 180-220 and a
maximum offset of ca. 7 km. The highest quality data were registered on
the eastern and in the central part of the profile with numerous shot
and receiver gathers exhibiting clear reflectivity and first breaks up
to maximum offsets (Figure 3). The western parts of the profile show
noisier data due to line position close to a big city and major roads.
Generally, reflections are more continuous on some receiver gathers,
showing that geophone-ground coupling in the city environment is key to
acquiring quality data. For this reason, when possible, processing steps
were carried out on receiver gathers. An interesting phenomenon of this
dataset is the strong presence of back-scattering of surface-waves in
some parts of the profile (Figure 4). Given their clear locations, they
are used in this study to complement the interpretation of imaging
results.