NATURAL HAZARDS ASSOCIATED WITH GLACIERS AND PERMAFROST

Introduction and definitions Glacier and permafrost hazards are related to glacial, paraglacial, and periglacial phenomena and processes. Though usually defined more narrowly, we subsume here in the context of hazards any perennial land surface ice body as glacier. The glacial, paraglacial, and periglacial environment is defined, respectively, as the zone of glaciers or their action, the non-glacial zone directly conditioned by glaciation or deglaciation, and the non-glacial zone in cold regions with frost action being the predominant geomorphic process. Often, the periglacial zone is characterized by permafrost (lithospheric material with negative temperatures throughout 2 or more years). Glacier and permafrost hazards are, thus, connected to glaciers and their present or past actions, and to year-round negative ground temperatures and related processes. Hazards associated to glaciers and permafrost are best treated together in an integrative way, because the environments they origin from are often in direct contact and the relevant processes interact. Disasters associated to the glacial, paraglacial, and periglacial environment can cause thousands of casualties in one event. Related damages or mitigation costs are on the order of several hundred million EUR as a longterm annual average global sum (Kaab et al., 2005b). Glacier and permafrost-related problems and threats include glacierand permafrost-related floods, stable and unstable glacier length changes as well as glacier fluctuations, glacierand permafrost-related mass movements,