This book is about marine seismic sources, their history, their physical
principles and their deconvolution. It is particularly accented towards
the physical aspects rather than the mathematical principles of
signature generation in water as it is these aspects which the authors
have found to be somewhat neglected. A huge amount of research has been
carried out by both commercial and academic institutions over the years
and the resulting literature is a little daunting, to say the least. In
spite of this, the subject is intrinsically very simple and relies on a
very few fundamental physical principles, a somewhat larger number of
heuristic principles and a refreshingly small amount of blunderbuss
mathematics. As such it is still one of those subjects in which the
gifted practical engineer reigns supreme and from which many of the
important advances have originated. In Chapter 1 of the book, the
underlying physics and concepts are discussed, including pressure and
wave propagation, bubble motion, virtual images and the factors
determining choice of source. In marine reflection seismology, almost
all of the seismic data acquired currently is done with either the
airgun or the watergun, which rely on the expulsion of air and water
respectively to generate acoustic energy. As a consequence, the
discussion in this chapter is geared towards these two sources, as is
much of the rest of the book.
