Volcanic Processes

Volcanic eruptions are fascinating manifestations of the Earth's dynamic inte­ rior which has been cooling for the past several billion years. The planets of the solar system originated some 4.5 billion years ago from the same gas and dust cloud created by the big bang. Some of the gas collapsed by the gravitational force to form the Sun at the center, while the whirling disk of gas and dust around the Sun subsequently cooled and lumped together to form larger and larger lumps of materials or planetesimals. These planetesimals collided fre­ quently and violently and in the process liberated heat that melted the material in them. With time this material gradually cooled and formed the planets of the solar system. During the second half of the twentieth century the theory of plate tectonics of the Earth became established and demonstrated that our planet is covered with six large and many small plates of the lithosphere. These plates move over a highly viscous lower part of the Earth's upper mantle and contain the continental and oceanic crusts. The lower mantle extends below the upper mantle until it meets the core that is more than half the diameter of the entire globe (12,740 km). The inner core consists mostly of iron and its temperature is about 5000 kelvin, whereas the liquid outer core is turbulent, rotates faster than the mantle, consists primarily of iron, and is the source of the Earth's magnetic field.

`Dr. Dobran is to be congratulated on having covered the basic physics of virtually all aspects of volcanology in so much detail. This will be an invaluable reference work for established specialists in volcanology. It will also provide an excellent starting point for new researchers wishing to become familiar with the quantitative aspects of this field.' Lionel Wilson, Emeritus Professor of Earth and Planetary Sciences, Lancaster, UK `Dr. Dobran has clearly taken particular care in the writing and documentation of the Volcanic Processes. The book offers a good balance between various ingredients from mechanics, geophysics, and chemistry. The text is practically self-contained in spite of its multidisciplinary nature; all terms, expressions, and mathematical formulas are clearly explained. The book contains many exercises and examples, and these always pertain to the subject matter at hand. This is a very strong asset from the point of view of pedagogy. The author has presented a rich historical background. This gives a vivid and entertaining style. The book is not neutral. It reflects the strong involvement of its author in the matter of volcanic eruptions, his case studies (Vesuvio), and his latent catastrophism. This is quite unusual in science books, which normally exhibit no personal feeling. The treatment, although aimed at advanced undergraduate and first-year graduate students, is up-to-date and full of useful data. This book will also be very useful to specialists in geology, geophysics, and volcanology. I recommend it highly.' Gérard A. Maugin, Laboratoire de Modelisation en Mécanique, Université Pierre et Marie Curie, Paris, France