Glaciers, second edition. By Michael Hambrey and Jürg Alean. Cambridge, U.K., and New York: Cambridge University Press, 2004. 394 pp. $60.00. ISBN 0521828082.
The second edition, like its predecessor, describes glaciers from a broad perspective. The authors discuss not only glaciers past and present, but their effects on the landscape and their relation to man's activities. The book is written for the non-specialist, but both specialist and non-specialist will be impressed by the astonishing collection of photographs on almost every page, and their wide geographic coverage. The specialist will also enjoy the review of the broader field into which his specialty fits, and in the process may be stimulated to think about fundamental issues. For example, we are told that retreating glaciers tend to have low-angle snouts, which is true. But how well do we really understand the underlying physics?
The book is an expanded and updated version of the first edition, and has mostly new photographs. The first half contains what might be considered a descriptive and unusually well-illustrated version of the conventional material covered by a course in glaciology, telling us “how glaciers work.” It is followed by chapters dedicated to Antarctica (not Greenland) and volcanoes. Then come chapters dealing with such topics as glaciers and landscape development, wildlife, benefits and hazards, glacial changes on time scales of a few years to a few million years, and climate and sea level change. The book concludes with a provocative discussion of the future of glaciers, the role of mankind in shaping that future, and the implications for living conditions on earth.
The reader will be pleased to find writing that is clear and entertaining. In a book with wide coverage but finite length, the authors have had to make decisions about allocation of space. Whether the choices are optimum is a matter of opinion, but I felt that the balance was excellent. Of course, one can always think of improvements in such a comprehensive work. For example, there is discussion about how the size and shape of a glacier affects the time scale for response to climate (a popular topic in specialists' circles), but no parallel discussion about the amplitude of the response. By demonstrating how a small change in the equilibrium line altitude (ELA) of a low-slope glacier can remove most of the accumulation area, it would be easy to show how the geometric factors which determine the time scale tend also to determine the amplitude. A long flat glacier may have a longer “time scale” for response to climate than a short steep one, but the ultimate response, at least to a permanent change, will be much larger.
Also, but through no fault of its own, the book follows some bad habits common among specialists. For example, given the rapidity with which glaciers change, we should get into the habit of dating all glacier photos when we publish them; in the case of this book, potential research value would be added to an excellent photo collection. We should not say “meltwater” when we mean “water” in general. We should make a more careful distinction between glacier “advance” and “motion.” Finally, it could be argued that we should not say “sliding” when we mean “basal motion,” which includes deformation of subglacial sediments. Admittedly the non-specialist (or even the specialist) reader will be unaware of most of these distinctions, perhaps rightly so.
In an endnote, the authors tell us that although they have tried to explain how glaciers work, “… first and foremost [they] have tried to convey the beauty and fascination of glaciers.” In my opinion they have succeeded at both. They have produced a significant and enjoyable book that merits the wide audience at which it is aimed.
