The revolution is so recent, however, that while those taking part are still abuzz with excitement, the broader community is only just beginning to see snippets of results. In new his book Sound Images of the Ocean Peter Wille takes a major step towards bringing these new capabilities and all they have to offer to a much wider audience. At the same time he has produced a remarkable collection of very high-quality images that will prove invaluable to those immersed in the field.

In Sound Images of the Ocean the author brings together and carefully documents and attributes a phenomenal array of modern sonar images that clearly demonstrate our new ability to capture and visualise a broad range of ocean processes. But this is far more than a picture-book. Peter Wille, professor at the University of Hamburg and former director of both the German Armed Forces Research Institute and the NATO Undersea Research Center, is a senior statesman of the marine acoustics community. He has called upon this background to ‘set the scene’ for the sonar images, providing more than sixty pages of introductory material on the nature of sound in the sea. This material describes, in rela-tively simple terms, the basic physics behind sound transmission in the sea, the character-istics of echo sounders, and the constant trade-offs between propagation, resolution and noise. While the detail provided is less than that required for a textbook in underwater acoustics, it serves as a very fitting introduction to the collection of images that follow; a brief appendix and literature index provide more depth for those that are interested.

Following on his background material, Peter Wille presents nearly 140 pages of mostly colour images of sea-floor topography, ranging from beautifully rendered global scenes to detailed depictions of sedimentary bedforms. The images have extensive captions car-rying detailed explanations of the geological significance of the image, as well as a de-scription of the sensors used to collect the data. The images are grouped by tectonic set-ting (e.g. mid-ocean ridges, convergent margins, passive margins, etc.) and as such they serve as an invaluable resource for both students and teachers of Earth processes. Special sections also focus on geographical regions of particular interest, including the Arctic, the Antarctic, the Mediterranean and the Baltic.

Subsequent chapters deal with sonar imagery of ocean volume (currents, marine mam-mals, gas, and even sea-floor characterisation) and truly spectacular imagery of manmade objects including cables, pipelines and a number of wrecks and other marine archaeologi-cal artefacts. Supplementing the text is a CD with digital versions of many of the images, as well as software that allows interactive 3D exploration of some of the datasets.

Throughout the text the author’s knowledge of, and passion for, the subject is evident. He has provided us with a ‘one-stop shopping’ place for sea-floor imagery. This conven-ience, combined with the in-depth explanations and exceptionally high quality of the im-ages (including digital versions on the CD), make this book an essential companion to all of us interested in understanding the oceans.

Peter Wille, Sound Images of the Ocean in Research and Monitoring, with contributions from 120 sound-image authors and marine experts from 22 countries. Springer 2005, XLII, 472 p. 452 illus., 391 in colour, with CD-ROM. Hardcover ISBN: 3-540-24122-1, US$129 / €99.95 plus VAT.