Geoscience Reference
In-Depth Information
Fig. 2.16
Land acquisition examples.
2.3
3-D land acquisition
There are a number of major differences between marine and land acquisition. In the lat-
ter, the shots and receivers are decoupled, the survey area has non-uniform topography,
and obstacles and hazards are more common. Land operations occur in a variety of
areas, from baking deserts to frozen wastes, and from jungles to cities
(fig. 2.16
)
. Each
survey needs to be designed specifically for the terrain and region covered so as to
ensure good data quality and optimised turnaround time, while being non-intrusive
to the environment and ensuring the safety of the seismic operation's crew and local
inhabitants.
The favoured land source is the vibrator since it is the most efficient to operate,
has little environmental impact, and has better control over the source characteristics
than the main explosive-based alternatives. The vibrator is a large truck that contains
a mechanical device for shaking the ground through a controlled set of frequencies.
Full details are given in the acquisition references included at the end of this chapter.
