Snow and Ice-Related Hazards, Risks, and Disasters

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• Publisher: Academic Press
• Year: 2014
• ISBN:
  9780123964731
• Topic: Physical Sciences
• Subtopic: Geology & Earth Sciences

Snow and Ice-Related Hazards, Risks, and Disasters provides you with the latest scientific developments in glacier surges and melting, ice shelf collapses, paleo-climate reconstruction, sea level rise, climate change implications, causality, impacts, preparedness, and mitigation. It takes a geo-scientific approach to the topic while also covering current thinking about directly related social scientific issues that can adversely affect ecosystems and global economies.

• Puts the contributions from expert oceanographers, geologists, geophysicists, environmental scientists, and climatologists selected by a world-renowned editorial board in your hands
• Presents the latest research on causality, glacial surges, ice-shelf collapses, sea level rise, climate change implications, and more
• Numerous tables, maps, diagrams, illustrations andphotographs of hazardous processes will be included
• Features new insights into the implications of climate change on increased melting, collapsing, flooding, methane emissions, and sea level rise

Chapter 1

Snow and Ice-Related Hazards, Risks, and Disasters

A General Framework

Wilfried Haeberli¹, and Colin Whiteman^{2 1}Department of Geography, University of Zurich, Switzerland ²School of Environment and Technology, University of Brighton, UK

Abstract

Snow and ice constitute the cryosphere on Earth and influence human activities at various scales of time and space. Through their proximity to phase-change thresholds, they are strongly linked to climatic conditions and presently subject to rapid changes induced by ongoing trends of global warming. Hazards, risks, and disasters related to snow and ice not only result from direct impacts on humans and their infrastructure by, for instance, snow avalanches, floods from glacial lakes, or accelerated erosion of permafrost coasts, they are also a consequence of the expansion of human activities into previously avoided dangerous regions, such as new shipping routes in the polar ocean, and tourist installations in cold mountains that are becoming ice free. The loss of goods and benefits from reducing or even vanishing cryosphere components constitutes serious threats to human well-being through, for example, diminishing meltwater supply in high-mountain rivers during dry seasons or rising global sea level. Further protection, mitigation, and adaptation procedures, combined with modern observational technologies will be required to anticipate, monitor, and deal with the challenges created by complex and highly interconnected geo- and ecosystems under conditions of growing disequilibrium.

Keywords

Climate change; Cryosphere; Disasters; Hazards; High mountains; Ice; Polar regions; Risks; Snow

1.1. Introduction

Snow and ice are common components of natural and human environments on Earth (UNEP, 2007; Singh et al., 2011; Williams and Ferrigno, 2012). They constitute the cryosphere (Figure 1.1). Via climatic conditions and the water cycle, their existence and variability affects humans around the globe, even in places where this may not be directly recognized or obvious. Dramatic changes in ice volumes during most recent Earth history, the Pleistocene ice ages, created an important cryogenic heritage in many landscapes, including lakes and rivers, vegetation and fauna (Swift et al., 2014). As with all hazardous components of the global environment, living with snow and ice involves costs and benefits.

FIGURE 1.1 The cryosphere.

From UNEP (2007). Free download.

Before introducing the range of hazards associated with snow and ice that are covered in this volume, it is important to differentiate clearly between the concepts of hazard, risk and disaster because these terms do not refer to the same idea and yet are sometimes used indiscriminately. Essentially, a hazard is a feature or situation that can be expected to impact negatively on the life, health, property, or environment of humans if an event (e.g., an avalanche) or significant change (e.g., loss of Arctic sea ice) occurs. Risk is a more complex concept involving not only the probability that a hazardous event or significant change will occur, but also the expected loss or cost and the degree to which this can be mitigated. Risk related to cryospheric hazards must therefore be considered from the points of view of both the physical hazard and the human response (Whiteman, 2011). Thus risk increases as human contact with the cryosphere becomes more frequent and more extensive. Population growth, especially in naturally hazardous regions, such as alpine mountains, automatically raises the level of risk, and the development of infrastructure may both enhance the accessibility of more hazardous locations and increase the value of potential losses. In any particular event or situation, the scale of loss of both life and property may be of such great magnitude that the outcome is described as a disaster.

Physical impacts from snow and ice can be both primary/direct (avalanches, for example), and secondary/indirect (for example, sea-level rise). Corresponding hazards are largely related to the inherent physical characteristics of snow and ice (Arenson et al., 2014). These undergo melting and freezing, they move (creep, slide, fall), float, are heavy en masse, are sometimes hard and sometimes brittle or ductile. Each of these characteristics may contribute, in isolation or in combination, to the type and intensity of ice- and snow-related hazards, and they often interact with other components of the environment. Threats and damage can arise over short as well as long time periods, at local to regional, continental, and even global scale.

Snow and ice are especially sensitive to climate change. Impacts of ongoing and potentially accelerating human-induced global warming are a serious concern (e.g., IPCC, 2013) and increasingly predominate in discussions about hazard assessment and risk reduction by adaptation, mitigation, and prevention measures. A critical aspect is the relatively high melt/freeze threshold of ice, only about 15 °C below the mean temperature of the Earth's atmosphere. Considering the variability of atmospheric temperatures around this mean, the high frequency with which the melt/freeze threshold is crossed is not surprising, and obviously contributes to frequent and extensive hazard events.

Snow and ice are also often of major importance well beyond their geographical extent, producing meltwater for irrigation, industry, and households during dry seasons (Seibert et al., 2014). In colder regions, river and lake ice may facilitate traffic in remote areas. Thus changes in the temporal or spatial distribution of snow and ice may have a wide range of unwelcome consequences. Although the exact details of future climatic conditions are still difficult to predict, climate change will strongly if not dramatically change snow and ice conditions on Earth, increasing the impacts of many hazards in the short, medium, and long term, even though some hazards and some hazardous locations may cease to exist as ice disappears completely from some locations. The environmental changes caused by the ongoing loss of snow and ice may constitute an equally strong if not even stronger long-term challenge. The different responses to climate change of the various environmental components induce growing disequilibria in complex environmental geo- and ecosystems. The rate of change as influenced by human interference with the climate system will be critical in terms of the scale of hazards and our ability to adapt in time to new conditions. The slower the rate of change, the more degrees of freedom that will remain for difficult decisions to be taken and policies to be implemented to accommodate environments in which the prevalence of snow and ice is greatly reduced.

1.2. Costs and Benefits: Living with Snow and Ice

The components of the cryosphere—continental ice sheets, glaciers, river and lake ice, sea ice, seasonal snow, and frozen ground—strongly differ with respect to their volume, spatial extent, and occurrence in time (Table 1.1). These three aspects govern their primary environmental functions, the economic and social benefits they provide and the degree of hazard they may pose to humans, with their associated risks and potential for disasters (UNEP, 2007).

The largest ice bodies on Earth are the continental ice sheets. With their enormous mass, white/cold surfaces (Figure 1.2), and the direct ice contact of their margins with the sea, ice sheets are drivers of the global environment, actively influencing physical and living conditions worldwide (Bentley et al., 2007). Via atmospheric and ocean circulation, the presence of a large ice sheet covering the continent of Antarctica at the South Pole for the past millions of years, and for millions of years to come, has a strong cooling influence on the global climate (Ohmura, 2014). This cooling effect, together with long-term fluctuations of incoming solar radiation due to variations in the Earth's orbit around the sun, enables the development of ice ages, with their dramatic effects. One of these effects concerns the formation and disappearance of other ice sheets, and associated large changes in sea level (Allison et al., 2014). The growth of the Laurentide Ice Sheet over large parts of North America alone lowered sea level by at least 100 m a...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• Editorial Foreword
• Foreword by Charles Harris
• Preface
• Chapter 1. Snow and Ice-Related Hazards, Risks, and Disasters: A General Framework
• Chapter 2. Physical, Thermal, and Mechanical Properties of Snow, Ice, and Permafrost
• Chapter 3. Snow and Ice in the Climate System
• Chapter 4. Snow and Ice in the Hydrosphere
• Chapter 5. Snow, Ice, and the Biosphere
• Chapter 6. Ice and Snow as Land-Forming Agents
• Chapter 7. Mountains, Lowlands, and Coasts: the Physiography of Cold Landscapes
• Chapter 8. Integrated Approaches to Adaptation and Disaster Risk Reduction in Dynamic Socio-cryospheric Systems
• Chapter 9. Integrative Risk Management: The Example of Snow Avalanches
• Chapter 10. Permafrost Degradation
• Chapter 11. Radioactive Waste Under Conditions of Future Ice Ages
• Chapter 12. Snow Avalanches
• Chapter 13. Glacier Surges
• Chapter 14. Glacier-Related Outburst Floods
• Chapter 15. Ice Loss and Slope Stability in High-Mountain Regions
• Chapter 16. Catastrophic Mass Flows in the Mountain Glacial Environment
• Chapter 17. Hazards at Ice-Clad Volcanoes: Phenomena, Processes, and Examples From Mexico, Colombia, Ecuador, and Chile
• Chapter 18. Floating Ice and Ice Pressure Challenge to Ships
• Chapter 19. Retreat Instability of Tidewater Glaciers and Marine Ice Sheets
• Chapter 20. Ice Sheets, Glaciers, and Sea Level
• Index