This book provides state of art reviews on the applications of U-Th series nuclides to 'time' and 'tag' a variety of processes occurring in aquatic systems. The processes addressed would include, among others, chemical weathering on continents, dating of groundwaters and movement of radio-nuclides through them, submarine groundwater dischare into the ocean, ocean circulation and mixing on various spatial and temporal scales and partical dynamics and chemical scavenging in the sea. This field is going through a resurgence because of major advancement in the U-Th measurement techniques, made since the 1990's. This has opened up new opportunities in the use of these nuclides to probe into aquatic processes in greater detail. The focus of this volume though is on aqeuous system processes, there are also chapters/sections on atmosphere and sediments which closely interact with water bodies.

* this book provides state of art reviews on the applications of U-Th Series nuclides to 'time'and 'tag' key processes occurring in aquatic systems.

* the book is self-contained, each chapter presents nuclide source functions, processes regulating their distributions and models used to describe them.

* the book emphasizes current thinking in the field and future directions.