Cryosphere science research has been advancing at a robust pace in recent years. Geocryology, as defined by the authors, is the study of the effects of ground temperature below 0°C on the surface layers of the Earth’s crust. The “geo” modifier stems from the recognition that, increasingly, resources are extracted from permafrost regions, compelling the need for a better understanding of the geological, engineering, social, and environmental issues associated with resource extraction. How permafrost distribution around the globe responds to climate change is neither in much doubt nor needs much introduction. However, the impact of the permafrost responses on landforms, ecosystems, carbon cycle, and water resources remains much less studied. This book, Geocryology: Characteristics and Use of Frozen Ground and Permafrost Landforms, covers these topics and is therefore a timely contribution. The 765-page book is hefty, and so is the expansiveness in its coverage of historical development and new advances in research and applications in geocryology. It is a rich accumulation of the authors’ decades of experiences on permafrost and frozen ground from around the globe, particularly North America, the Arctic, and the Qinghai-Tibet Plateau.
The book consists of eighteen chapters that are grouped into three parts: permafrost characteristics, permafrost landforms, and use of permafrost areas. The first part has four chapters that deal with the characteristics of permafrost, soil processes, and permafrost development and distribution. An exhaustive list of terminologies at the beginning of this part is well explained and should serve as an excellent reference for many. There are also in-depth discussions about the basic processes associated with these terms, and simple but effective conceptual illustrations accompany the text. Permafrost distribution can be a rather dry topic, but the systematic presentation in this book is intellectually satisfying. The authors put permafrost distribution in the context of high-latitude and high-altitude regimes, temperature and precipitation phase diagrams, and various tools for mapping permafrost distribution that include direct field measurements, geophysical methods, as well as modeling tools.
The second part consists of seven chapters that cover various landforms from more commonly known or easily observed surface features, such as patterned ground and pingos, to lesser known landforms or those hidden in the subsurface, such as thermal karst and ice caves. The authors put the variety of landforms in a temperature regime that spans from −20°C to just higher than 0°C in three types of permafrost settings: continuous, discontinuous, and sporadic. Mechanics and theoretical analysis are presented to explain the physics behind generating those landforms. Most landforms are put in a Freezing Index–Thaw Index phase diagram, which illustrates the temperature conditions under which these landforms exist. Such a systematic view and synthesis analysis are again intellectually satisfying and will be appreciated by readers. Mass wasting in permafrost lands has been occurring pervasively, but has been reported more frequently in recent years. An extensive survey of mass-wasting sites is timely and useful, which not only contributes important content to a relatively new category of geohazards, but also helps increase the awareness of the scientific community and the general public.
The final part of the book, on the use of permafrost areas, is loaded with engineering practices and technologies unique to development in permafrost regions. A brief history of human utilization of permafrost by the Russians and the indigenous people in North America is a good read. The coverage about foundations for highways, railways, and buildings is extensive. Relevant to the foundations is a presentation on theoretical and mechanical fundamentals such as soil consolidation, soil mechanical behaviors, and heat transfer in soils, which will be very useful for a broader range of readers. The chapters about oil, gas, and mining are particularly informative and balanced. The authors provide a good overview of the unique challenges associated with the exploration and development of these resources. The authors also devote pages to the environmental impacts of developing these resources, from water-use demand to waste disposal.
One area that I wished this book covered more extensively is the relationship of permafrost dynamics to the water cycle. Water undoubtedly is a central element in many permafrost stories and permafrost thawing impacts the water cycle at various spatial and temporal scales. As permafrost thaws, the hydrological properties of active layers change, which has a direct impact on how water flows through active layers and how surface water and groundwater interact. The short- and long-term of such impacts are potentially critical to water-resource development in permafrost regions, yet the topic of water cycle and permafrost remains under-studied.
As cryosphere science starts to permeate the educational curriculum, future editions that provide easily adoptable materials for classrooms will be even more appreciated by educators and students. Additionally, physics-based numerical models are increasingly used to simulate the freeze and thaw of permafrost, and how water flow is coupled to heat transport and soil mechanics in studying permafrost hydrology and mechanics. More attention to this growing area of research would also serve readers well.
Overall, this is an excellent reference book for permafrost researchers. It is expansive in spatial extent and comprehensive in fundamentals. The illustrations are rich with field photos, monitoring data, model results, and conceptual sketches. This book can be an invaluable reference for many for years to come.