Glaciers and ice caps are spectacular and important parts of the global cryosphere. Their fluctuations dramatically affect the water cycle - locking up fresh water as they grow and advance, causing the sea level to rise as they thaw and retreat. Despite the much larger reservoir of ice in our planet's ice sheets, ice caps and glaciers presently dominate ice-sourced sea level rise and are projected to continue to do so over the coming century. Moreover, mountain glaciers provide crucial water supplies to hundreds of millions of people. Therefore it is imperative to monitor glaciers on a global scale, assess their mass balance and predict their future behavior. With the rapid development of satellite and aerial based remote sensing sensors, abundant data, characterizing the evolution of glacier extent, elevation and surface properties become now also available. The bottleneck has shifted from obtaining data to the processing of information from which we gain new knowledge about past and present glacier behavior, essential to model the response of the cryosphere, to changes in the Earth's climate system.
Bringing together experts in remote sensing, glaciology, meteorology and geography, this book provides an overview of remote sensing data acquisition and processing methods for investigating glacier change. It showcases results of the OMEGA (Development of Operational Monitoring System for European Glacier Areas - synthesis of Earth observation data of the present, past and future) project, which aimed at developing new methods for mapping glacier extent and topography. What makes the book a valuable resource to students and practitioners in natural sciences, especially in glaciology and remote sensing, is that in addition to reviewing the different remote sensing methods it provides background in glaciology as well as in the physics of glacial remote sensing.
Chapter 1 reviews the basic principles of remote sensing, the main sources and interactions of electromagnetic radiation as well as the different sensor types. Chapter 2 briefly summarizes the principles of glacier formation, mass balance changes and ice flow. It also elaborates on the different methods used for determining glacier mass balance. Chapter 5, Physics of glacier remote sensing, starts with a description of the structure and deformation of glacier snow and ice, followed by a review of the interaction of electromagnetic radiation with ice and snow in the different wavelength bands (visible, near infrared, thermal and microwave/radar). I suggest reading Chapter 5 after Chapter 2, because it provides an excellent linkage between the introductory chapters and Chapter 3, which reviews the glacier parameters monitored by remote sensing. A very informative chapter on glacier remote sensing history concludes the introductory, background material (Chapter 4).
The next part of the book, Chapters 6-11, introduces the different remote sensing methods used for glacier mapping, namely terrestrial photogrammetry (Chapter 6), aerial photogrammetry (Chapter 7), optical imaging (Chapter 8), SAR imaging and inSAR (Chapter 9), airborne laser scanning (Chapter 10) and ground penetrating radar (Chapter 11). As it is quite common for edited books, the level of detail and writing style varies significantly from chapter to chapter. Some of the chapters have a narrow focus, for example Chapter 8, Optical remote sensing of glacier extent describes the use of image ratios for delineation of glaciers. However, other topics, such as inSAR and ground penetrating radar, receive an in-depth, advanced treatment. In particular, Chapter 11 provides an excellent review of glaciological applications of ground penetrating radar (or I would rather call it radio echo sounding or ice penetrating radar) measurements, not available in other textbooks. Chapters 12-14 deal with applications, including different change detection methods as well as visualization and accuracy assessment of glacier elevation and volume changes. The final chapters (15-16) reinforce the importance of remote sensing in present and future glacier monitoring.
This book is one of the very few remote sensing books solely dedicated to the cryosphere. It provides a good introduction to state-of-the-art remote sensing methods used in glaciology and illustrates their use with examples from a wide range of applications. Many of the examples originate from the OMEGA project. This is also true for most of the chapter authors of the book.
In general, the book is informative and has high quality illustrations. On the downside the chapters differ greatly in quality and their sequence is somewhat arbitrary at times. Finally, with a price tag of 150 USD, only those who are really very interested in the subject may buy the book.
