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Fig. 4.53 A set of synthetic seismograms
simulating a seismic section across a zone
of irregular sandstone geometry. (From
Neidell & Poggiagliolmi 1977.)
firing rate achieved, to enable surveys to be carried
out continuously from a moving vehicle.
The source and hydrophone array are normally towed
at shallow depth but some deep-water applications uti-
lize deep-tow systems in which the source and receiver
are towed close to the sea bed. Deep-tow systems over-
come the transmission losses associated with a long water
path, thus giving improved penetration of seismic/
acoustic energy into the sea bed. Moreover, in areas of
rugged bathymetry they produce records that are much
simpler to interpret; there is commonly a multiplicity
of reflection paths from a rugged sea bed to a surface
source-detector location, so that records obtained in
deep water using shallow-tow systems commonly ex-
hibit hyperbolic diffraction patterns, bow-tie effects
and other undesirable features of non-migrated seismic
sections.
In place of the digital recorder used in multichannel
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