Isabelle Gärtner-Roer

Mountain permafrost: development and challenges of a young research field

An overview is given of the relatively short history, important issues and primary challenges of research on permafrost in cold mountain regions. The systematic application of diverse approaches and technologies contributes to a rapidly growing knowledge base about the existence, characteristics and evolution in time of perennially frozen ground at high altitudes and on steep slopes. These approaches and technologies include (1) drilling, borehole measurement, geophysical sounding, photogrammetry, laser altimetry, GPS/SAR surveying, and miniature temperature data logging in remote areas that are often difficult to access, (2) laboratory investigations (e.g. rheology and stability of ice– rock mixtures), (3) analyses of digital terrain information, (4) numerical simulations (e.g. subsurface thermal conditions under complex topography) and (5) spatial models (e.g. distribution of permafrost where surface and microclimatic conditions are highly variable spatially). A sound knowledge base and improved understanding of governing processes are urgently needed to deal effectively with the consequences of climate change on the evolution of mountain landscapes and, especially, of steep mountain slope hazards as the stabilizing permafrost warms and degrades. Interactions between glaciers and permafrost in cold mountain regions have so far received comparatively little attention and need more systematic investigation.

Rock Glacier Degradation and Instabilities in the European Alps: A Characterisation and Monitoring Experiment in the Turtmanntal, CH

Global climate change is impacting sensitive alpine cryogenic regions, through slope instabilities in rocks and soils. Significant temperature increase at the air-ground surface interface may be accompanied by increased rainfall, more extreme storms and additional severe rise in mean global temperatures in the coming decades, enhancing risk of mass movement hazards to human life and infrastructure. Rock glaciers and degrading permafrost on steep Alpine slopes are particularly susceptible to warming and phase change in either massive or interstitial ground ice, which may lead to release of water, accelerated motions, initiation of landslides and instabilities. Accumulated failure in soil elements, determined on artificial frozen specimens of rock glacier materials at temperatures below 0 °C, is linked to these processes at field scale. A geophysical and geotechnical field characterisation and monitoring experiment is being conducted on a rock glacier that is undergoing thermally induced creep and growth of thermokarst. Preliminary investigations are described in this contribution.

Introduction: Global glacier monitoring— a long-term task integrating in situ observations and remote sensing

This book focuses on the complexities of glaciers as documented via satellite observations. The complexities drive much scientific interest in the subject. The essence—that the world’s glaciers and ice caps exhibit overwhelming retreat—is also developed by this book. In this introductory chapter, we aim at providing the reader with background information to better understand the integration of the glacier-mapping initiative known as Global Land Ice Measurements from Space (GLIMS, http://www.glims.org ) within the framework of internationally coordinated glacier-monitoring activities. The chapter begins with general definitions of perennial ice on land and its global coverage, followed by a section on the relation between glaciers and climate. Brief overviews on the specific history of internationally coordinated glacier monitoring and the global monitoring strategy for glaciers and ice caps are followed by a summary of available data. We introduce the potential and challenges of satellite remote sensing for glacier monitoring in the 21st century and emphasize the importance of integrative change assessments. Lastly, we provide a synopsis of the book structure as well as some concluding remarks on worldwide glacier monitoring.

Preface: The mountain cryosphere - a holistic view on processes and their interactions

Gruber, S., Egli, M., Gärtner‐Roer, I. and Hoelzle, M., 2012. Preface: The mountain cryosphere – a holistic view on processes and their interactions. Geografiska Annaler: Series A, Physical Geography, ••, ••–••. doi:10.1111/j.1468‐0459.2012.00468.x

Ice and Snow as Land-Forming Agents

Abstract Many high-latitude and high-altitude regions are covered by ice and snow for substantial parts of the year, and typically, the landscape of such regions bears the strong imprint of ice- and snow-related processes operating over Quaternary to modern timescales. Despite strong research interest in the nature, rate, and efficacy of cold-region geomorphic processes, most research has been devoted to glacier and permafrost phenomena, whereas comparably few studies have quantitatively addressed the role of snow as a land-forming agent. In this chapter, we review the current research on land-forming processes related to glacial erosion and deposition; permafrost and periglacial processes; and snow-related processes such as nivation, snow creep, and snow avalanching. Our objective is to highlight those questions that drive current research and those that seem sufficiently promising to further our understanding of geomorphic form and process in the cryosphere. We do so bearing in mind that such process knowledge is essential for successfully predicting form and process, and hence avoiding snow- and ice-related hazards. We discuss whether certain aspects concerning the role of ice and snow as land-forming agents may have been overrated or underrated, if not overlooked, in the context of comprehensive studies on landscape evolution in polar and high mountainous terrain. We conclude by outlining a number of recommendations for future research in the field.