The science of geomorphology,in its more restrictive sense, is primarily concerned with the study of surface features, which are due to processes originating outside the solid Earth (exogenetic processes). In its widest sense, it naturally includes both the description of present-day landscapes and the elucidation and explanation of their histories. Until relatively recently geomorphology has been a purely descriptive science spattered only by occasional mathematical outbursts contributed by physicists, geophysicists and mathematicians in their search for reasonable and rigorous explanations of the more commonplace features of the Earth’s surface. To many geomorphologists the introduction of a mathematically expressed law, an integral or an equation relating to a land-surface feature is foreign, but as this science evolves and advances it is inevitable that geomorphologists must think, record and analyse their observations in a more rigorous fashion.
In his book, Dr. Scheidegger has valiantly attempted the long overdue union of field observation and equation, which he has achieved with some measure of success. In discussing the six main topics of the book—mechanics of slope formation, river bed processes, development of drainage basins, theory of aquatic effects, niveal effects (why not a less cacophanous and better-known expression") and theory of aeolian features—the author has found it necessary to review briefly the resultant forms described in the literature and to introduce the reader to relevant basic physical principles, the understanding of which is essential before delving into the major part of the book. For instance, amongst other principles the physical properties of ice, the theory of plasticity and the various flow laws of ice are quoted.
In some thirty pages, devoted to “niveal effects”, the reader is taken carefully through a critical discussion of theories concerning ice ages, followed by the theory of longitudinal flow and sliding of glaciers, the dynamics of glacier snouts, the formation of transverse crevasses and the geomorphological effects of longitudinal glacier motion. Three-dimensional ice movement (including a brief reference to ice caps), pingos and “niveal” solifluction all find their place in the discussion. In this remarkably short space the author has succeeded in stating and illustrating clearly all the relevant arguments and equations that he has combed from the more important recently published (and older) literature. The theory of glacier motion is disseminated through the pages of countless journals in English and a dozen foreign languages, but here there is an adequate summary to encourage the young glaciologist to deeper reading.
Although the origin of the shape of drumlins and pingos is considered at relative length, the reader might be disappointed to find that more important geomorphological features, such as the transverse profile of glaciated valleys, eskers, moraines and glacial cirques, are briefly dismissed. In view of the vast current literature on all these subjects, they could warrant more attention in a future edition of the book.
Although the critic could well suggest a more unified approach to the discussion of each topic by bringing descriptive observation into closer contact with the mathematical analysis, it is clear that a considerably enlarged volume would be required to cover the ground adequately. The selected references, given at the bottom of each page, should assist the reader in this respect. In spite of certain difficulties of expression and odd printing errors (especially in the mathematics), the author has succeeded admirably in breaking through the harrier that has long baffled the average geomorphologist, and it is hoped that this will lead to the clearer understanding and investigation of many more of the lesser known surface features of the Earth.
