Typical Aspects of Cold Regions Shorelines

Abstract

Cold regions shorelines (about one-third of the world's coastline) do not differ much from those of mid- and low-latitude regions because the fundamental factors governing their development (lithology, structure, tectonics) are nearly the same. Major features (cliffs, platforms, drowned valleys, dunes and beaches) are also found in the three major morphoclimatic regions (warm, temperate, cold). Many differences, however, do exist in the details and in the processes involved in shoreline development. There are two main categories of factors to consider. Two climatic factors (ice and frost) play an important role in shaping cold regions coasts, whereas the geological background, particularly the Quaternary heritage (glaciations and marine submergence) is of major importance for an adequate knowledge of cold regions coastal features (paraglacial vs. periglacial shorelines).|The role of ice and frost in the different coastal environments in cold regions is generally relatively well known. Detailed studies, however, when compared to mid- and low-latitude regions, are much less common and specialized. Large areas have not been surveyed adequately, and data on processes, particularly over the long-term, are missing almost everywhere. This is especially true in the Southern Hemisphere. The coastal environments for which data exist are mainly deltas, beaches, tidal flats and margins, cliffs and platforms, and the shallow inner portion of the shelf.|First, three typical aspects will be examined and discussed briefly: ice action on rocky shorelines and in intertidal marshes, frost action on rocky shorelines and in intertidal marshes, and the debris content of the ice cover - a prerequisite for ice rafting. Finally, cold coastal dunes and aeolian processes will be summarized.|A better knowledge of cold coastal features and processes is necessary not only to preserve these fragile environments, but also for planning adequate economic development and a better use of this natural resource.