The Norwich Symposium, 'Radionuclides in the Study of Marine Proces ses', is a sequel to the very successful conference held at Cherbourg, France in June 1987. The international character of the meeting has been maintained with thirty-eight contributions, from seventeen countries, being accepted for oral presentation. For many years, the radioactive properties of the naturally occurring radionuclides have been used to determine their distributions in the marine environment and, more generally, to gain an understanding of the dynamic processes which control their behaviour in attaining these distributions. More recently the inputs from human activities of both natural and artificial (i.e. man-made) radionuclides have provided additional opportunities for the study of marine processes on local, regional and global scales. Because the sources of artificial radionuclides are often reasonably well defined in space and time, and because a wider range of elements is represented, new viewpoints for the study of processes have become available. Although it is outside the scope of this Symposium, it must be acknowledged that the radiological protection requirements for radioactive waste disposal prac tices to be based on a sound scientific understanding of radionuclide behaviour in the sea have also provided a very strong impetus for the studies.

Major advancement in the U-Th measurement techniques since the 1990's have resulted in new opportunities for the use of these nuclides to probe into aquatic processes in greater detail. U-Th Series Nuclides in Aquatic Systems provides state-of-the-art reviews on the applications of U-Th series nuclides to "time" and "tag" in a variety of processes occurring in aquatic systems. - State of art reviews on the applications of U-Th Series nuclides to 'time'and 'tag' key processes occurring in aquatic systems. - Self-contained, each chapter presents nuclide source functions, processes regulating their distributions and models used to describe them - Emphasizes current thinking in the field and future directions

This book on Marine Radioactivity sets out to cover most of the aspects of marine radioactivity which have been the focus of scientific study in recent decades. The authors and their reviews divide into topic areas which have defined the field over its history. They cover the suite of natural radioisotopes which have been present in the oceans since their formation and quantitatively dominate the inventory of radioactivity in the oceans. Also addressed are the suite of artificial radionuclides introduced to the oceans as a consequence of the use of the atom for development of nuclear energy, nuclear weapons and various applications of nuclear science. The major source of these continues to derive from the global fallout of atmospheric tests of nuclear weapons in the 1950s and 1960s but also includes both planned and accidental releases of radioactivity from both civilian and military nuclear technology. The other division of the major study direction depends on whether the objective is to use the radionuclides as powerful tools to study oceanic processes, to describe and understand the ocean distribution of the various natural or artificial radionuclides or to assess the different radionuclides' impact on and pathways to man or marine organisms. The oceans cover 70% of the Earth's surface and thus contains a corresponding large share of the Earth's radioactivity. Marine Radioactivity covers topics of recent scientific study in this young field. It examines both natural radioactivity (radioactivity naturally present in oceans since their formation) and artificial radioactivity (radioactivity introduced by man and use of atomic and nuclear energy) with regard to possible effects on the global environment.

ABSTRACT: Naturally-occurring radioisotopes are ubiquitous in nature, and as such, there are many opportunities for researchers to use them as environmental tracers. Their associated radioactive decay rates provide an inherent time clock that often makes these radioisotopes more effective chemical tracers than other substances, since they can help assess the temporal component of a particular process. Radioisotopes were employed in this study to examine different coastal oceanographic processes that have far reaching consequences. A review of various measurement methods for assessing Ra-226 concentrations, a valuable tracer employed throughout most of this dissertation, is presented. This is followed by applying natural radioisotopes to study various oceanographic processes in China, Hawaii, and a river system in the southeastern United States.