Volcanoes: Crucibles of Change

_Volcanoes: Crucibles of Change_ by Richard V. Fisher, Grant Heiken, and Jeffrey B. Hulen is a fascinating and very well-written look at volcanoes, including their formation, structure, dangers, benefits, and how they have affected human history. The book is richly illustrated with photographs, maps, and fascinating diagrams explaining volcanic processes. Part one consisted of four chapters that looked at the geology of volcanoes. Important to understanding volcanoes is knowing where they form; they can appear over subduction zones (where one tectonic plate is pushed under another; the subduction of the Pacific plate under the American plate produces the volcanoes of the Cascade Mountains), extensional boundaries (where plates move apart, mainly between plates on the seafloor), and over hot spots (thermal plumes rising through the mantle than can be well away from either subduction zones or extensional boundaries). Also important to understanding volcanoes is knowledge of the composition of the magma that forms them. Magma containing less than 55% silica is called basaltic and is very fluid and has low-viscosity. It can easily form large lava flows and gas can rapidly escape from it, forming huge fountains (the authors compared it to the ease with which steam escapes from rapidly boiling water). Rhyolite lava on the other hand is comprised of over 70% silica, is very viscous, and gas does not readily escape from it unless the pressure is big enough (think of how hot oatmeal spatters explosively). Basalt lava generally forms beneath or within oceanic plates, rhyolite lava beneath or within a continental plate, and a third type, andesite lava (between 55% and 70% silica), where the two types of plate overlap. Volcanoes may take a variety of forms. Composite volcanoes or stratovolcanoes, such as Mount St. Helens and Mount Fuji, are graceful, solitary, often quite high and covered in snow or ice and are comprised of innumerable layers of rubble and debris from previous eruptions. Lava domes are protrusions of lava on the outside slope of many composite volcanoes or within their craters, built by the slow extrusion of viscous silica-rich magma. Calderas (from Spanish for "cauldron") are very large craters formed when the ground surface collapsed as the result of the extrusion of very large amounts of ash, pumice, and rock and can be quite large. Cinder cones or scoria cones are relatively small volcanoes, high mounds with small craters at the top, comprised of basaltic fragments called cinders or scoria, rocks that contain an abundance of bubble-like chambers. They often occur in clusters and on the slopes of other types of volcanoes. Maars are small volcanoes with wide craters that formed from the sudden explosion that occurred when rising magma came into contact with groundwater or surface water. Shield volcanoes are broad and have low slopes and are constructed of solidified basaltic lava that was originally in a highly fluid state. Littoral

I recommend this book most highly. It is well-organized, easily read by anyone with a high school education and a limited scientific background, and all-encompassing on the subject of volcanoes. The latest developments in volcanic petrology, pyroclastic flow study, caldera formation, supervolcanic eruptions and their horrific consequences, and the like are superbly covered. Additionally, the book contains excellent narratives of nearly all significant late 20th Century eruptions, such as Pinatubo, El Chichon, St. Helens, and Paricutin. The research is copious, and the results highly accurate.The book has been well-proofed, with the pleasurable consequence that distortive prose, inaccurate figures, and like blips are virtually non-existent. A fellow reviewer has stated that plate tectonics is not well-covered, but this writer's view is that the scope of the book lies beyond such basics. Anyone unfamiliar with basic volcanological concepts should first read "Teach Yourself Volcanoes", and then move into this book.Again, I enjoyed this book to the hilt, and would prize it above most other books on the subject. I strongly believe it is the best non-technical book on the subject.

Neither too little or too much, Volcanoes: Crucibles of Change is the best volume I have ever read on Volcanology. Written for the intelligent layperson, the book never talks down to its reader or loses them in mult-semicolon sentances of unintelligble jargon as so many other books by scientists do. If you want the latest theories on volcanoes, this is th book for you. I was especially surprised by how many dormant/active volcanoes there are in the lower 48. And as one who has flown from the U.S. to Japan, the chapter on planes and volcanoes was both fascinating and scary.

A brilliant book for any volcanoholic. I am a geology student hoping to proceed to volcanology, and thoroughly enjoyed this book just for the sake of a good read on a great subject.

This book is enjoyable to read: a great narrative that covers a wide range of topics about volcanoes: famous eruptions, effects on climate, how they provide resources, how they can adversely affect us, and more. The text has a lot of depth, but is cohesive and flows well. The diagrams are nicely done too. At the end of the book, the reader finds many helpful resources for volcano tourism.