PrefaceMoving water has a special fascination, and the regular tidal movements of coastal seas must have challenged human imagination from earliest times. Indeed, the ancients who were able to link the regular movements of the sea to the movements of the sun and moon regarded tides as a tangible terrestrial manifestation of the powers of the celestial gods. For them the tides had religious significance; for us there are obviously many practical and scientific reasons for needing to know about and understand the dynamics of the oceans and coastal seas.Modern practical studies are concerned with problems of marine transport, coastal erosion and the design of coastal defences against flooding. Interest in mean sea-level changes has recently focused attention on the possibility of significant increases over the coming century as a result of global warming. Scientifically, in addition to their position as a branch, perhaps the oldest branch, of physical oceanography, tides have a controlling influence on many marine biological and geological processes. One of the fascinations of studying tides is the diversity of the applications.During the past two decades, mainly as a result of developments in instrument design and in the computer sciences, our understanding of tides and their related phenomena has made considerable advances. The aim of this book is to present modern tidal ideas to those who are not tidal specialists, but for whom some tidal knowledge is involved in their own professional or scientific field. These include hydrographers, marine and coastal engineers, geologists who specialize in beach or marine sedimentation processes, and biologists concerned with the ways in which living organisms adapt to the rhythms of the sea.Some of the material presented here was originally prepared for a course of lectures in Liverpool University to third-year Combined Honours students, whose academic backgrounds varied from pure mathematics to field geology. This range of previous scientific experience inevitably causes difficulties in determining the level of mathematical treatment which should be adopted. In this book I have tried to keep the mathematics as simple as is consistent with a proper physical explanation, while developing the non-mathematical discussions in an essentially independent yet parallel way. Sections which may be omitted by the non-mathematical reader are marked with an asterisk.Discussions of the engineering applications of tides are based on several years of experience giving advice to consultants and to Government Departments on behalf of the Proudman Oceanographic Laboratory at Bidston Observatory. Many of my colleagues on the staff of the Laboratory have given me advice and constructive criticism during the preparation. To them and to many other friends and associates I extend my grateful thanks. In particular, it is a pleasure to thank Graham Alcock, M. Amin, Trevor Baker, David Blackman, Peter Claridge, Hilary Faull, Roger Flather, Tony Heathershaw, John Howarth, Ian James, Kathy Jones, Trevor Norton, Lesley Rickards, Ralph Rayner, Alun Thomas, Phillip Williamson, and Philip Woodworth for helpful comments on earlier versions of the text. It is also a pleasure to acknowledge specific or general guidance during the development of my ideas from Duncan Carr Agnew, David Cartwright, Mike Collins, Keith Dyer, Norman Heaps, Chester Jelesnianski, Geoff Lennon, Nick McCave, Robin Pingree, John Simpson, Ian Vassie and Klaus Wyrtki. Finally, I am grateful to my family for tolerating and even encouraging this personal indulgence through the evenings and weekends of four long winters. Cirencester, June, 1987 DAVID PUG
